Method and apparatus for controlling internal heat generating circuit

ABSTRACT

In a computer system constituted by a portable computer and a deskstation used to expand the function of the portable computer, the portable computer has a communication connector used for communication with the deskstation, in addition to a connector for connecting a system bus in the portable computer to the deskstation. Similarly, the deskstation also has a communication connector. When the portable computer is set at a predetermined position of the deskstation, these connectors are connected to each other before the system bus is connected to an expansion device of the deskstation. By using the communication connectors to perform communication between the portable computer and the deskstation, disconnection between the system bus and an expansion connector or forced suspend processing of the portable computer is executed before the portable computer in a power ON state is mounted in the deskstation. In addition, a lock mechanism is provided to lock the portable computer with the deskstation. The lock mechanism is operated/released by registering/deleting a password. Even when a power supply unit having a plurality of power supply outlets is externally provided to the deskstation, processing for sequentially enabling the power supply outlets is executed. Temperature control in the portable computer is also executed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a computer system and, moreparticularly, to a computer system having a computer main body and anexpansion unit capable of being freely attached/detached to/from thecomputer main body.

[0003] The present invention also relates to a computer system and, moreparticularly, to a computer system having a computer main body, a portreplicator for relaying connection to an externally connectedequipment., and an expansion unit loading an expansion equipment forexpanding the function therein.

[0004] The present invention also relates to an electronic equipmentsuch as a computer system and, more particularly, to a controller,constituted as a one-chip controller by a semiconductor integratedcircuit, for handling clock and digital signals, and an electronicequipment using the one-chip controller.

[0005] The present invention also relates to a computer system such as apersonal computer incorporating a CPU board and, more particularly, to acomputer system having a cooling control mechanism for a CPU chipmounted in the CPU board or other heat generating components.

[0006] 2. Description of the Related Art

[0007] In recent years, various personal computers of a laptop ornotebook type, which can be easily carried and operated by a battery,have been developed. A portable computer of this type is constitutedsuch that an expansion unit can be attached thereto as needed to expandthe function.

[0008] The expansion unit has a plurality of expansion connectors.Various option cards can be attached to the connectors. Additionally, inorder to suppress power consumption in a state without connection of thecomputer main body, in some expansion units, the voltage of a specificpin is monitored to detect connection of the expansion unit, and someexpansion units can be powered on only when the computer main body isconnected.

[0009] However, to use a mounted option card, the system configurationinformation of the portable computer must be rewritten forreconfiguration of the system. The system configuration information isnormally rewritten at the time of starting the system on the basis ofsetup information or the like, which is set by the user. Conventionally,therefore, when the expansion unit is mounted in the computer main bodyin a power ON state, the computer main body cannot recognize thepresence of the expansion unit, and the option card of the expansionunit cannot be used.

[0010] Recently, an operating system (OS) or BIOS (Basic Input/OutputSystem) having a function of reconfiguring the system during startingthe portable computer has been developed. By using an operating systemor BIOS of this type, the system environment can be changed duringstarting the system into an environment allowing the use of the optioncard.

[0011] However, when the expansion unit is mounted in the computer mainbody in a power ON state, an unexpected current flows from the computermain body to the option card due to hot swap or the like. This may causedestruction of the option card of the expansion unit. Even ifdestruction of the option card is prevented, disadvantages such ashangup of the computer main body may be generated.

[0012] For this reason, actually, the expansion unit cannot be mountedduring starting the system of the computer main body (in an ON state).

[0013] In addition, recent portable computers which are connected(docked) to expansion units are largely improved in performance.Furthermore, in recent years, a variety of optional equipments have beendeveloped.

[0014] In these situations, various function expansion mechanisms arerequired to expansion units, and accordingly, the packaging density ofcomponents in a unit becomes higher to make a unit housing bulky. Inaddition, a power supply unit in the expansion unit has a higher powerand becomes heavy.

[0015] Therefore, when an expansion unit having a desired function ismanufactured using the conventional manufacturing technique, the unitmain body becomes bulky and heavy. A large space is needed to set theunit, resulting in difficulty in handling.

[0016] In the conventional expansion unit of this type, a power supplyunit is incorporated in the unit to apply a power supply voltage to eachsection in the unit. For this reason, when the packaging density ofcomponents in the unit becomes higher, heat or noise generated from thepower supply unit largely influences each component in the unit andposes a problem of reliability.

[0017] In the conventional expansion unit of this type, power suppliesof the expansion unit and the personal computer mounted in the expansionunit are independently ON/OFF-controlled. Therefore, an erroneousoperation may be caused by a shift of the power supply states.

[0018] In the conventional expansion unit of this type, the personalcomputer mounted in the expansion unit can be arbitrarily detached. Forthis reason, disadvantages such as data destruction by a detachingoperation during the operation are likely to occur to degrade thesecurity.

[0019] In the conventional expansion unit of this type, when an optionalunit such as a hard disk unit is to be mounted, a tool such as a driveris used to partially disassemble the housing of the expansion unit, andthe optical unit such as a hard disk unit is fixed at a predeterminedposition in the housing. Thereafter, the housing is assembled to storethe optical unit in the expansion unit. Conventionally, storage orexchange of an optional unit is not facilitated, and much time and laborare needed.

[0020] In the conventional expansion unit of this type, when a personalcomputer is to be attached/detached, the power ON/OFF operation of thepower supplies of the personal computer and the expansion unit must beindependently performed in accordance with a predetermined feed/stopsequence, resulting in poor operability.

[0021] In the conventional expansion unit of this type, when thepersonal computer is mounted in the expansion unit, I/O ports of thepersonal computer, which include a printer connection port, a serial(RS-232C) port, and a CRT (R, G, and B) connection port, are closed. Forthis reason, the expansion unit also has the similar I/O ports, and alarge number of connection interfaces must be conventionally provided tothe unit housing. Therefore, as the unit becomes bulky, a large numberof connector wiring lines are needed, resulting in complex structure ofthe expansion unit. In addition, in the above conventional structure, anexpansion unit having I/O ports must be used even in a systemconfiguration using no I/O port, which poses an economical problem.

[0022] As a controller constituted as a one-chip controller by asemiconductor integrated circuit for handling clock and digital signals,various controllers constituting a CPU chip or a family thereof areavailable. Such a one-chip controller for handling clock and digitalsignals greatly increases its processing speed in recent years. Alongwith this, an increase in power consumption, and accordingly, anincrease in chip temperature pose serious problems.

[0023] As for a CPU chip, to solve the above problems, countermeasuresincluding a reduction in power consumption by application of a CMOS, areduction in voltages, improvement of fins have been made. On the otherhand, a clock speed for determining the processing speed of the CPUincreases from several MHz to several tens MHz in recent years. Evenwith the above countermeasures, the power consumption and temperature ofthe chip greatly increase.

[0024] As for the mounting environment of the CPU chip, further size andweight reduction and a smaller setting space are required to theequipment main body of, e.g., a portable computer. Accordingly, thepackaging density of electronic components per unit volume furtherincreases.

[0025] When the CPU chip is mounted in such an environment, it isdifficult to ensure a space for mounting fins. In addition, since manyheat generating elements are mounted in the periphery, a mechanical heatdissipation effect cannot be expected. In this case, if an increase intemperature of the CPU chip is left as it is, the CPU itself erroneouslyoperates to cause troubles such as hardware abnormality and circuitdestruction, resulting in difficulty in restoration, as a matter ofcourse.

[0026] Conventionally, a method is applied in which a temperature fuseor an element for measuring the temperature of the CPU chip is mountedat a position relatively close to the CPU chip, thereby switching theCPU clock in accordance with a temperature detected by the element.

[0027] In the conventional temperature control of this type, however,the internal temperature of the CPU chip cannot be directly measured. Itmust be indirectly measured through a package or a print board, so achange in temperature cannot be rapidly and accurately recognized. Forthis reason, conventionally, clock switching control must be performedin accordance with a set temperature having a large margin for safety.Therefore, the high-speed performance of the CPU cannot be sufficientlyexhibited.

[0028] As described above, in the conventional one-chip controller forhandling clock and digital signals of the CPU chip or the like, a changein temperature in the chip cannot be rapidly and accurately recognized,and clock switching control must be performed in accordance with a settemperature having a large margin for safety. Therefore, the performanceof the CPU cannot be sufficiently exhibited.

[0029] In an electronic equipment such as a portable computer mountedwith a CPU board, the processing performance (processing speed) isdetermined by the CPU clock frequency. More specifically, as the clockfrequency is raised within a range of a defined threshold clockfrequency of the CPU chip, the processing performance increases.However, with a higher processing speed, the power consumption increasesin accordance with the clock frequency, and is accordingly, the heatgeneration amount of the CPU chip also increases.

[0030] In a portable computer mounted with a CPU board of this type, tosufficiently exhibit the performance of the CPU chip, various types ofchip cooling methods/mechanisms for dissipating heat generated in theCPU chip and suppressing an increase in temperature of the CPU chip areproposed and realized.

[0031] As a countermeasure for suppressing an increase in temperature ofthe CPU chip, a method is conventionally applied in which an ambienttemperature in the periphery of the CPU chip is detected, and the clockfrequency is controlled in accordance with the detection output. Morespecifically, when the ambient temperature in the periphery of the CPUchip amounts to a set temperature, the CPU clock frequency is lowered.Alternatively, the CPU clock frequency is controlled to be inverselyproportional to the ambient temperature in the periphery of the CPUchip.

[0032] In the conventional temperature control, however, heat generatedby the heat generating portion of the CPU chip is transferred inperipheral air, and the diffused ambient temperature is detected by atemperature sensor to control the clock frequency. With this structure,a relatively large time delay occurs until the heat of the CPU chip isreflected on the CPU clock frequency control. In addition, the accuratetemperature of the heat generating portion cannot be detected. Sincetemperature control cannot be precisely and accurately performed, and alarge margin must be ensured for an operating limitation temperature,the CPU chip cannot be operated at an almost threshold frequency.Therefore, conventionally, the performance of the CPU chip cannot besufficiently used to realize high-speed processing by CPU clock at analmost threshold frequency.

[0033] When the temperature of the CPU chip amounts to a hightemperature which does not allow continuation of a normal operation, thesystem operation must be stopped at that point of time. Otherwise, itmay cause not only destruction of data which is being processed but alsoabnormality of hardware or software, resulting in difficultly inrestoration.

[0034] When a portable computer is mounted in a function expansion unitfor expanding the function of the portable computer, the heatdissipation port of the portable computer is closed by the functionexpansion unit, and the portable computer indirectly receives heatgenerated in the function expansion unit. For this reason, in along-time use, the temperature in the housing of the portable computermay abnormally increase depending on the peripheral environment toaccordingly cause destruction of data which is being processed orabnormality of hardware.

[0035] As described above, in the conventional CPU temperature controlmeans, a relatively large time delay occurs until the temperature of theCPU chip is reflected on the CPU clock control, and highly precisetemperature detection cannot be performed. For this reason, CPU chiptemperature control cannot be precisely performed, and the performanceof the CPU chip cannot be sufficiently used to realize a stablehigh-speed operation of the CPU chip at an almost threshold frequency.

[0036] When the temperature of the CPU chip amounts to a hightemperature which does not allow continuation of a normal operation, thesystem operation must be stopped at that point of time. Otherwise, itmay cause not only destruction of data which is being processed but alsoabnormality of hardware or software, resulting in difficultly inrestoration. In addition, when a portable computer is mounted in afunction expansion unit for expanding the function of the portablecomputer, the heat dissipation port of the portable computer is closedby the function expansion unit, and the portable computer indirectlyreceives heat generated in the function expansion unit. For this reason,in a long-time use, the temperature in the housing of the portablecomputer may abnormally increase depending on the peripheral environmentto accordingly cause destruction of data which is being processed orabnormality of hardware.

SUMMARY OF THE INVENTION

[0037] It is an object of the present invention to provide a computersystem which allows attachment/detachment of an expansion unit whilekeeping a computer main body in a power ON state.

[0038] It is the second object of the present invention to provide acomputer system having a compact and lightweight function expansion unitwhich can be easily handled and operated and also stably maintain areliable operation with an economically advantageous structure.

[0039] It is the third object of the present invention to provide aone-chip controller capable of rapidly and accurately recognizing achange in temperature in a chip.

[0040] It is the fourth object of the present invention to provide anelectronic equipment using a one-chip controller, which can rapidly andaccurately reflect a change in temperature in the one-chip controller tocircuit control in the one-chip controller, thereby efficiently drivingand controlling the one-chip controller in a state close to an operatinglimitation.

[0041] It is the fifth object of the present invention to provide acomputer system/electronic equipment mounted with a CPU board and havinga detachable expansion unit, which can rapidly and accurately reflectthe temperature of the CPU chip on chip temperature control andsufficiently use the performance of the CPU chip, thereby realizing ahigh-speed operation of the CPU chip at an almost threshold frequency.

[0042] According to the first aspect of the present invention, there isprovided a computer system comprising: a computer having first andsecond connectors, a bus, and connection control means forenabling/disabling connection between the second connector and the bus;and an expansion unit capable of being attached/detached to/from thecomputer, wherein the expansion unit has a third connector connectableto the first connector and connected to the first connector when thecomputer is set at a mounting position of the expansion unit, a fourthconnector connectable to the second connector and arranged to be free tomove between a first position where the fourth connector is disconnectedfrom the second connector and a second position where the fourthconnector is connected to the second connector when the computer is setat the mounting position, at least one expansion connector connected tothe fourth connector and capable of being mounted with an expansiondevice, a loading mechanism for moving the fourth connector between thefirst position and the second position, and expansion unit control meansfor outputting a connection request signal for connection between thesecond connector and the fourth connector to the computer through thethird connector when the computer is set at the mounting position,moving the fourth connector from the first position to the secondposition by driving the loading mechanism in accordance with apermission signal sent from the first connector, and outputting aconnection completion signal upon completion of movement of the fourthconnector to the second position, the connection control means is set todisable connection between the second connector and the bus in advance,and the computer includes computer control means for outputting thepermission signal to the expansion unit through the first connector inaccordance with the connection request signal, and controlling theconnection control means to enable connection between the secondconnector and the bus when the computer is in a power ON state uponreception of the connection request signal.

[0043] In the computer system the expansion unit includes an ejectswitch for designating to detach the fourth connector of the expansionunit from the second connector, and means for sending a detachmentrequest signal for detachment of the fourth connector to the computerthrough the third connector when the eject switch designates to detachthe fourth connector from the second connector, moving the fourthconnector from the second position to the first position by driving theloading mechanism in accordance with the detachment request signal sentfrom the computer, and outputting a separation completion signal uponcompletion of movement of the fourth connector to the first position,and the computer includes means for, when the computer is in a power ONstate, controlling the connection control means to enable connectionbetween the second connector and the bus in accordance with thedetachment request signal and outputting a detachment permission signalthrough the first connector.

[0044] With this structure, connection of the expansion connector of theexpansion unit is informed to the computer main body before actualelectrical connection with the system bus of the computer main body. Forthis reason, even when the user attaches the expansion unit to thecomputer main body in a power ON state, disadvantages such asdestruction of the expansion device such as an option card of theexpansion unit are prevented. Therefore, so-called hot docking can beperformed. In addition, when the eject switch is turned on by the user,detachment of the expansion unit is informed to the computer main bodybefore the expansion connector of the expansion unit is electricallydisconnected from the system bus of the computer main body, andprocessing such as electrical disconnection between the expansionconnector and the system bus is automatically executed. For this reason,hot undocking can be realized in which the user detaches the computermain body in a power ON state from the expansion unit.

[0045] According to the second aspect of the present invention, there isprovided a computer system comprising: a computer having a firstconnector, a bus, a second connector connected to the bus, and anonvolatile memory; and an expansion unit capable of beingattached/detached to/from the computer, wherein the expansion unit has athird connector connectable to the first connector and connected to thefirst connector when the computer is set at a mounting position of theexpansion unit, a fourth connector connectable to the second connectorand arranged to be free to move between a first position where thefourth connector is disconnected from the second connector and a secondposition where the fourth connector is connected to the second connectorwhen the computer is set at the mounting position, at least oneexpansion connector connected to the fourth connector and capable ofbeing mounted with an expansion device, a loading mechanism for movingthe fourth connector between the first position and the second position,and expansion unit control means for, when the computer is set at themounting position, outputting a connection request signal for connectionbetween the second connector and the fourth connector to the computerthrough the third connector and moving the fourth connector from thefirst position to the second position by driving the loading mechanismin accordance with a permission signal sent from the first connector,and the computer includes computer control means for, when the computeris in a power ON state, executing suspend processing in whichinformation necessary for resuming processing which is being executed isstored in the nonvolatile memory to interrupt the processing and set apower OFF state in accordance with the connection request signal andthereafter outputting the permission signal to the expansion unitthrough the first connector.

[0046] In the computer system, the expansion unit includes an ejectswitch for designating to detach the fourth connector of the expansionunit from the second connector, and means for sending a detachmentrequest signal for detachment of the fourth connector to the computerthrough the third connector when the eject switch designates to detachthe fourth connector from the second connector, and moving the fourthconnector from the second position to the first position by driving theloading mechanism in accordance with the detachment request signal sentfrom the computer, and the computer includes means for, when thecomputer is in a power ON state, executing the suspend processing inaccordance with the detachment request signal and outputting adetachment permission signal through the first connector.

[0047] With this structure, according to the present invention,connection of the expansion connector of the expansion unit is informedto the computer main body before actual electrical connection with thesystem bus of the computer main body, and processing such as the powerOFF operation of the computer main body is automatically executed. Forthis reason, even when the user attaches the expansion unit to thecomputer main body in a power ON state, disadvantages such asdestruction of the expansion device such as an option card of theexpansion unit are prevented. Therefore, so-called hot docking can beperformed. In addition, when the eject switch is operated by the user,detachment of the expansion unit is informed to the computer main bodybefore the expansion connector of the expansion unit is electricallydisconnected from the system bus of the computer main body, andprocessing such as the power OFF operation of the computer main body isautomatically executed. For this reason, hot undocking can be realizedin which the user detaches the computer main body in a power ON statefrom the expansion unit.

[0048] According to the third aspect of the present invention, there isprovided a computer system comprising: a computer; and an expansion unitcapable of being attached/detached to/from the computer and constitutedby an expansion unit main body and a power supply unit, wherein thepower supply unit is connected to the expansion unit main body through acable and supplies a first power to the expansion unit through thecable, and the expansion unit main body includes at least one expansionconnector connectable to an expansion device for expanding a function ofthe computer, a mounting portion for mounting the computer, and a powersupply circuit for supplying an operating power to the expansion deviceon the basis of the first power supplied from the power supply unit whenthe computer is mounted at the mounting portion.

[0049] In the computer system, the power supply unit has a plurality ofpower supply outlets, and the expansion unit main body includes meansfor enabling the plurality of power supply outlets in a predeterminedorder with predetermined time lags.

[0050] In the computer system, the computer includes means fordesignating to start/stop supplying the first power through theexpansion unit main body and the cable when the computer is mounted atthe mounting portion. In addition, the expansion unit has a plurality ofpower supply outlets, and the computer includes means for enabling theplurality of power supply outlets in a predetermined order withpredetermined time lags.

[0051] With the power ON/OFF sequence control function of the expansionunit main body and the feed/stop sequence control function of theplurality of power supply (AC) outlets, the power ON/OFF operationaccording to the start/end of operation of the entire system can befacilitated, thereby largely decreasing the work load. At the same time,an erroneous operation caused by a shift of power supply states can beprevented.

[0052] According to the fourth aspect of the present invention, there isprovided a computer system comprising: a computer; and an expansion unitcapable of being attached/detached to/from the computer, wherein theexpansion unit includes at least one expansion connector connectable toan expansion device for expanding a function of the computer, a mountingportion for mounting the computer, and a lock mechanism for fixing thecomputer at a predetermined position of the mounting portion when thecomputer is mounted at the mounting portion.

[0053] Since the expansion unit main body (DS) has the lock mechanismfor the mounted portable computer (PC), disadvantages such as datadestruction caused by a detaching operation during the operation can beprevented. At the same time, the portable computer (PC) is integratedwith the expansion unit main body (DS), thereby obtaining an effect forsecurity.

[0054] According to the fifth aspect of the present invention, there isprovided a computer system comprising: a computer having a firstconnector connected to a bus and at least one second connectorconnectable to an external device; a relay unit connected to thecomputer and having a third connector connected to the bus which relaysthe first connector, and at least one fourth connector connectable tothe external device which relays the second connector; and at least oneexpansion unit connectable to the relay unit, wherein the expansion unithas a mounting portion capable of being mounted with an expansion devicefor expanding a function of the computer, an internal bus connected tothe expansion device mounted at the mounting portion, a fifth connectorconnected to the internal bus, and a sixth connector connectable toeither the third connector or the fifth connector of another expansionunit. In the computer system, the first and second connectors arearranged on a rear surface of the computer, the relay unit is mounted onthe rear surface of the computer so as to have the third connector on alower surface and relays the first and second connectors of thecomputer, and the at least one expansion unit is mounted under thecomputer and the relay unit to overlap another expansion unit such thatthe bus of the computer is connected to the expansion device of theexpansion unit.

[0055] In the computer system with the above structure, a portablecomputer, a port replicator (relay unit), and a plurality of expansionunits can be connected. An additional expansion unit can be easilyconnected to this computer system, as needed. Therefore, a computersystem coping with the requirement of an operator can be flexiblyprovided.

[0056] According to the sixth aspect of the present invention, there isprovided an electronic equipment comprising: a processor incorporating adelay circuit element whose delay time changes depending on atemperature; a detection circuit, connected to the delay circuitelement, for detecting an internal temperature of the processor from achange in response, delay of the delay circuit element; and clockcontrol means for controlling a clock signal supplied to the processorsuch that an operating speed of the processor is decreased when theinternal temperature detected by the detection circuit exceeds a firsttemperature. The electronic equipment further comprises a nonvolatilememory, and means for causing the nonvolatile memory to storeinformation necessary for resuming processing which is being executed,thereby powering off the electronic equipment when the internaltemperature detected by the detection circuit exceeds a secondtemperature.

[0057] According to the seventh aspect of the present invention, thereis provided an electronic equipment comprising: a processor forcontrolling the electronic equipment; a detection circuit for detectingan internal temperature of the processor; and clock control means forcontrolling a clock signal supplied to the processor such that anoperating speed of the processor is decreased when the internaltemperature detected by the detection circuit exceeds a firsttemperature. The electronic equipment further comprises a nonvolatilememory, and suspend means for causing the nonvolatile memory to storeinformation necessary for resuming processing which is being executed,thereby powering off the electronic equipment when the internaltemperature detected by the detection circuit exceeds a secondtemperature. In addition, the electronic equipment further comprises afan for exchanging air in the periphery of the processor, a drivingcircuit for driving the fan, and means for controlling the drivingcircuit to cool the air in the periphery of the processor in accordancewith the internal temperature detected by the detection circuit.

[0058] According to this structure, a one-chip controller capable ofrapidly and accurately recognizing a change in temperature in the chipcan be provided. In addition, a change in temperature in the one-chipcontroller can be rapidly and accurately reflected on circuit control inthe one-chip controller, thereby efficiently driving and controlling theone-chip controller in a state close to an operating limitation.Therefore, in the computer system using the one-chip controller, optimaltemperature control can be executed.

[0059] According to the eighth aspect of the present invention, there isprovided a computer system comprising: a computer having a processor forcontrolling the entire computer; an expansion unit used to expand afunction of the computer and capable of being attached/detached to/fromthe computer; and a sensor for detecting a temperature of the processor,wherein the expansion unit includes a fan for exchanging air in theperiphery of the processor, a driving circuit for driving the fan, andcontrol means for appropriately setting the temperature of the processorby controlling the driving circuit in accordance with the temperaturedetected by the sensor.

[0060] According to this structure, air heated by a heat generatingportion in the portable computer is drawn on the deskstation side, orcooled air is blown from the deskstation side, thereby enablingappropriate temperature control. Therefore, the performance of the CPUchip can be sufficiently used to realize a high-speed operation of theCPU chip at an almost threshold frequency. In addition, since the fan isarranged on the deskstation side, the size of the portable computer canbe further reduced.

[0061] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outin the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate presently preferredembodiments of the invention and, together with the general descriptiongiven above and the detailed description of the preferred embodimentsgiven below, serve to explain the principles of the invention.

[0063]FIG. 1 is a perspective view showing the outer appearances of aportable computer and a deskstation, which constitute a computer systemaccording to the first embodiment of the present invention;

[0064]FIG. 2 is a view for explaining a set state of the computer systemshown in FIG. 1;

[0065]FIG. 3 is a block diagram showing the configuration of thecomputer system of the first embodiment;

[0066]FIG. 4 is a block diagram showing the circuit arrangement of apower supply unit shown in FIG. 3;

[0067]FIG. 5 is a circuit diagram for explaining signals related to adeskstation controller shown in FIG. 3;

[0068]FIGS. 6A and 6B are views for explaining an operation ofconnecting the portable computer to the deskstation in the computersystem of the first embodiment, in which FIG. 6A shows a state shift inconnection, and FIG. 6B is a flow chart for explaining communicationbetween the CPU of the portable computer, a power supply controller, andthe deskstation controller of the deskstation in connection;

[0069]FIGS. 7A and 7B are views for explaining an operation of detachingthe portable computer from the deskstation in the computer system of thefirst embodiment, in which FIG. 7A shows a state shift in detachment,and FIG. 7B is a flow chart for explaining communication between the CPUof the portable computer, the power supply controller, and thedeskstation controller of the deskstation in detachment;

[0070]FIG. 8 is a block diagram showing the configuration of a computersystem according to the second embodiment of the present invention;

[0071]FIG. 9 is a flow chart for explaining communication between theCPU of a portable computer, a power supply controller, the deskstationcontroller of a deskstation when the portable computer is connected tothe deskstation in the computer system of the second embodiment;

[0072]FIG. 10 is a flow chart for explaining communication between theCPU of the portable computer, the power supply controller, and thedeskstation controller of the deskstation when the portable computer isdetached from the deskstation in the computer system of the secondembodiment;

[0073]FIG. 11 is a block diagram schematically showing the structure ofa deskstation in a computer system according to the third embodiment ofthe present invention;

[0074]FIG. 12 is a block diagram showing the internal arrangement of apower supply unit in the computer system shown in FIG. 11;

[0075]FIG. 13 is a block diagram for explaining a lock mechanism andperipheral constituent elements related to the lock mechanism in thecomputer system of the third embodiment;

[0076]FIG. 14 is a view showing a connection example in which a portreplicator is mounted in a portable computer, and the portable computerand the port replicator are mounted in the deskstation in the computersystem of the third embodiment;

[0077]FIG. 15 is a block diagram schematically showing the configurationof the computer system, in which feed/stop control of the AC powersupplies of power supply outlets in the third embodiment is applied tothe first embodiment;

[0078]FIG. 16 is a flow chart for explaining an example of feed controlof the AC power supplies in FIG. 15;

[0079]FIG. 17 is a flow chart for explaining an operation of hot/coldinsertion of the portable computer with respect to the deskstation whenfeed control of the AC power supplies of the power supply outlets in thethird embodiment is applied to the first embodiment;

[0080]FIG. 18 is a flow chart for explaining the operation of lockmechanism control for connecting the portable computer to thedeskstation when the lock mechanism control in the third embodiment isapplied to the first embodiment;

[0081]FIG. 19 is a flow chart for explaining the operation of lockmechanism control for detaching the portable computer from thedeskstation when lock mechanism control in the third embodiment isapplied to the first embodiment;

[0082]FIG. 20 is a side view showing a connection state of a computersystem as a modification of the third embodiment, which is constitutedby the portable computer, the port replicator, and a plurality of isexpansion units;

[0083]FIG. 21 is a perspective view showing the outer appearance of thecomputer system shown in FIG. 20;

[0084]FIG. 22 is a block diagram showing the configuration of a systemaccording to the fourth embodiment of the present invention;

[0085]FIGS. 23A to 23C are sectional views showing mounting examples ofa temperature detector in the fourth embodiment;

[0086]FIG. 24 is a chart showing a relationship between various settemperatures in the fourth embodiment and a detected temperature, andtimings of control;

[0087]FIG. 25 is a chart showing a relationship between various settemperatures in the fourth embodiment and a detected temperature., andtimings of control;

[0088]FIG. 26 is a flow chart for explaining temperature control in thefourth embodiment;

[0089]FIG. 27 is a flow chart for explaining SMI processing of theprocessing shown in FIG. 26;

[0090]FIG. 28 is a view showing a mounting example of the temperaturedetector in the fourth embodiment;

[0091]FIG. 29 is a view showing a mounting example of the temperaturedetector in the fourth embodiment;

[0092]FIGS. 30A and 30B are timing charts for explaining clockretardation control in the fourth embodiment;

[0093]FIGS. 31A and 31B are timing charts for explaining clock stopcontrol in the fourth embodiment;

[0094]FIGS. 32A to 32C are timing charts for explaining HALT control inthe fourth embodiment;

[0095]FIGS. 33A and 33B are views showing the first example of acomputer system according to the fifth embodiment of the presentinvention, in which FIG. 33A is a perspective view showing the outerappearance of the computer system, and FIG. 33B is a block diagramshowing the configuration of the computer system;

[0096]FIGS. 34A and 34B are views showing the second example of thecomputer system according to the fifth embodiment of the presentinvention, in which FIG. 34A is a perspective view showing the outerappearance of the computer system, and FIG. 34B is a block diagramshowing the configuration of the computer system;

[0097]FIG. 35 is a view showing a mounting example (first variation) ofa sensor in the fifth embodiment;

[0098]FIG. 36 is a view showing a mounting example (second variation) ofthe sensor in the fifth embodiment;

[0099]FIG. 37 is a view showing a mounting example (third variation) ofthe sensor in the fifth embodiment;

[0100]FIG. 38 is a view showing a mounting example (fourth variation) ofthe sensor in the fifth embodiment;

[0101]FIG. 39 is a view for explaining a structure when the mountingexample shown in FIG. 35 is applied to the fourth embodiment;

[0102]FIG. 40 is a view for explaining a structure when the mountingexample shown in FIG. 36 is applied to the fourth embodiment;

[0103]FIG. 41 is a view for explaining a structure when the mountingexample shown in FIG. 37 is applied to the fourth embodiment;

[0104]FIG. 42 is a view for explaining a structure when the mountingexample shown in FIG. 38 is applied to the fourth embodiment;

[0105]FIG. 43 is a block diagram for explaining a modification of thefifth embodiment;

[0106]FIG. 44 is a block diagram for explaining a modification of thefifth embodiment;

[0107]FIG. 45 is a view showing the outer appearance of a control keyused in password registration/deletion processing of lock mechanismcontrol in the third embodiment; and

[0108]FIG. 46 is a flow chart for explaining password management usingthe control key shown in FIG. 45.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0109] Each embodiment according to the present invention will bedescribed below with reference to the accompanying drawings.

[0110]FIG. 1 is a perspective view showing the outer appearance of acomputer system according to the first embodiment of the presentinvention. This computer system is constituted by a portable computer 1and a deskstation 2. The portable computer 1 is a portable computer of alaptop or notebook type. The deskstation 2 is an expansion unitdetachably connected to the main body of the portable computer 1.

[0111] The portable computer 1 has a flat panel display unit 12 which isattached to the main body of the portable computer 1 to be free to pivotbetween an opening position and a closing position. The flat paneldisplay unit 12 at the closing position covers the main body of theportable computer 1, as shown in FIG. 1. At the opening position, theflat panel display unit 12 stands at the rear portion of the main bodyof the portable computer 1.

[0112] The deskstation 2 is used to expand the function of the main bodyof the portable computer 1. The housing of the deskstation 2accommodates a device for expanding the function of the portablecomputer 1, e.g., a CD-ROM drive or a hard disk drive. The deskstation 2also has slots with expansion connectors 21 a and 21 b for connectingvarious option cards.

[0113] An eject switch SW3 which is operated to eject the mountedportable computer 1 is arranged on the front surface of the housing ofthe deskstation 2. The housing of the deskstation 2 also has a flatmounting surface 22 for accommodating the main body of the portablecomputer 1. This mounting surface 22 has almost the same size as that ofthe bottom surface of the main body of the portable computer 1. Guideportions 23 and 24 for guiding the main body of the portable computer 1to the mounting position are formed at the left and right end portionsof the mounting surface 22. A first connector unit 25 is arranged at therear end portion of the mounting surface 22. The front surface of thefirst connector unit 25 is brought into contact with the rear surface ofthe portable computer 1 when the main body of the portable computer 1 isset at the mounting position.

[0114] A communication connector 26 and a detection switch SW1 arearranged on the front surface of the first connector unit 25. Thecommunication connector 26 is used for communication between theportable computer 1 and the deskstation 2 and connected to acorresponding connector arranged on the rear surface of the main body ofthe portable computer 1 when the main body of the portable computer 1 isset at the mounting position. The detection switch SW1 mechanicallydetects whether the main body of the portable computer 1 is set at themounting position. More specifically, when the main body of the portablecomputer 1 is set at the mounting position, the switch SW1 is depressedby the rear surface of the main body of the portable computer 1 andturned on to generate a pulse. As the detection switch SW1, an armatureis preferably used.

[0115] A second connector unit 27 is movably arranged on the uppersurface of the first connector unit 25. The second connector unit 27 ismoved between the rear and front end portions of the first connectorunit 25 by a driving mechanism including a motor and the like, asindicated by an arrow. Normally, the second connector unit 27 is fixedat the rear end portion of the first connector unit 25, as shown in FIG.1, and moved to the front end portion of the first connector unit 25upon setting the main body of the portable computer 1 to the mountingposition.

[0116] A connector 28 is arranged on the front surface of the secondconnector unit 27. The connector 28 is used to connect various expansiondevices in the expansion unit to the system bus of the portable computer1. The connector 28 is connected to a corresponding connector arrangedon the rear surface of the main body of the portable computer 1 when thesecond connector unit 27 is moved to the front end portion of the firstconnector unit 25.

[0117] When the main body of the portable computer 1 is to be set on thedeskstation 2, the user fits the rear portion of the main body of theportable computer 1 between the guide portions 23 and 24 on the frontsurface of the deskstation 2, as indicated by an arrow in FIG. 1,thereby mounting the portable computer 1 on the mounting surface 22.When the main body of the portable computer 1 is pushed by the user, themain body of the portable computer 1 is slid on the mounting surface 22along the guide portions 23 and 24 toward the first connector unit 25,thereby setting the main body of the portable computer 1 to the mountingposition where the rear surface of the portable computer 1 contacts thefront surface of the first connector unit 25.

[0118] At this time, the detection switch SW1 is turned on. Inaccordance with a pulse generated upon turning on the switch SW1, thedeskstation 2 recognizes setting of the main body of the portablecomputer 1. While the main body of the portable computer 1 is set on thedeskstation 2, only the communication connector 26 of the deskstation 2and a communication connector 13 of the portable computer 1 areconnected to each other, as shown in FIG. 2. At this time, the connector28 of the deskstation 2 is separated from an expansion connector 14 ofthe portable computer 1.

[0119] The deskstation 2 communicates with the portable computer 1 inresponse to the ON operation of the detection switch SW1. Thiscommunication is performed to inform the portable computer 1 of dockingof the deskstation 2. A connection request is sent from the deskstation2 to the portable computer 1 through the communication connectors 26 and13. The portable computer 1 performs processing necessary for dockingthe deskstation 2 in response to the connection request. Thereafter,upon reception of a connection permission signal from the portablecomputer 1, the deskstation 2 executes an auto loading operation to movethe second connector unit 27 to the front end portion of the firstconnector unit 25, thereby docking, i.e., connecting the connector 28 ofthe deskstation 2 to the expansion connector 14 of the portable computer1.

[0120] As described above, in this computer system, before the connector28 of the deskstation 2 is connected to the expansion connector 14 ofthe portable computer 1, the communication connector 26 of thedeskstation 2 is connected to the communication connector 13 of theportable computer 1 to perform communication between the deskstation 2and the portable computer 1. With this operation, the portable computer1 can execute processing necessary for docking the deskstation 2 beforethe bus of the portable computer main body is connected to thedeskstation 2.

[0121]FIG. 3 is a block diagram showing the system configuration of thecomputer system.

[0122] A CPU (Central Processing Unit) 111, a system controller 112, anda main memory 113 are arranged on the system board of the portablecomputer 1. The CPU 111 and the main memory 113 are connected to a CPUlocal bus 114 including a data bus with a 32-bit width. The CPU localbus 114 is connected to an ISA (Industrial Standard Architecture) systembus 115 including a data bus with a 16-bit width through the systemcontroller 112. The system bus 115 is connected to the expansionconnector 14 through a dock-control gate array (DOCK-CONT GA) 125.

[0123] In addition, various I/Os such as a BIOS ROM (Basic Input/OutputSystem Read-Only Memory) 116, a deskstation interface (DS I/F) 117, aninterrupt controller (PIC) 118, a system timer (PIT) 119, a real-timeclock (RTC) 120, and a keyboard controller (KBC) 121, a power supply(PS) 122, a power supply (PS) controller 123, and the dock-control gatearray (DOCK-CONT GA) 125 are arranged on the system board.

[0124] The deskstation interface (DS I/F) 117 is a communication unitprovided for communication with the deskstation 2 and connected to thecommunication connector 13. The deskstation interface 117 is alsoconnected to the system bus 115 for communication with the CPU 111 andat the same time connected to the power supply controller 123 forcommunication with the power supply controller (PS controller) 123. Ahardware interrupt signal is used for communication from the deskstationinterface 117 to the CPU 111. As the hardware interrupt signal, systemmanagement interrupt called an SMI is preferably used due to thefollowing reason. The SMI is a non-maskable interrupt with a priorityhigher than that of INTR or NMI (Non-Maskable Interrupt), which cancause the CPU 111 to execute a predetermined SMI service routine withoutinfluencing an application program which is being executed.

[0125] The deskstation interface 117 is backed up by a backup powersupply BK from the power supply 122 so that it can communicate with thedeskstation 2 even in the power OFF state of the portable computer 1.The deskstation interface 117 has a hardware structure to performprocessing according to the power ON/OFF state of the main body of theportable computer 1 in accordance with a dock request command (to bedescribed later).

[0126] The power supply controller 123 controls the power supply 122 andperforms the ON/OFF operation of the portable computer 1 in accordancewith the ON/OFF state of a power supply switch (P-SW1). The power supplycontroller 123 is backed up by the backup power supply BK and always setin an operative state even in the power OFF state of the portablecomputer 1 to perform predetermined processing. More specifically, thepower supply controller 123 performs a certain operation as far as abattery 125 is loaded in the computer main body, or an AC power supplyis connected to an AC adaptor 124. In addition, the power supply 122outputs a voltage VCC of +5V when the portable computer 1 is in a powerON state. The voltage VCC is applied to the various constituent elementsand at the same time to the connector 13. When the connector 13 isconnected to the connector 26 of the deskstation 2, the voltage VCC isapplied to a deskstation controller (DS controller) 211.

[0127] The dock-control gate array 125 controls connection between thesystem bus 115 and the expansion connector 14 on the basis of adesignation from the CPU 111. When the portable computer 1 is notconnected to the deskstation 2, the dock-control gate array 125 isdisabled. For this reason, the system bus 115 and the expansionconnector 14 are not connected.

[0128] The deskstation 2 also has the deskstation controller 211, anEEPROM (Electrically Erasable Programmable Read-Only Memory) 212, anauto loading mechanism 213, and a power supply unit 214 in addition tothe above-described expansion connectors 21 a and 21 b.

[0129] The deskstation controller 211 controls communication with theportable computer 1, and the auto loading control mechanism 213.Detection signals from the three detection switches SW1 to SW3 aresupplied to the deskstation controller 211. The detection switch SW1detects that the portable computer 1 is set at the mounting position ofthe deskstation 2, i.e., that the communication connectors 13 and 26 areconnected to each other. The detection switch SW2 detects that thesecond connector unit 27 is moved to dock the portable computer 1 withthe deskstation 2, i.e., that the expansion connectors 14 and 28 areconnected to each other. The detection switch SW2 is a mechanical switcharranged in a driving mechanism for moving the second connector unit 27and turned on when the second connector unit 27 reaches the mountingposition of the portable computer 1. As the detection switch SW2, aphotosensor or the like can be used. The detection switch SW3 is aneject switch which is operated by the user to detach the portablecomputer 1 from the deskstation 2. The eject switch SW3 is arranged onthe front surface of the main body of the deskstation 2. Instead ofusing the switch SW1, a predetermined pin of the connector 13 is pulledup on the portable computer 1 side, or a predetermined pin of theconnector 26 is pulled up on the deskstation 2 side. In this case,connection between the connectors 13 and 26 can be detected bymonitoring the voltage of the pin.

[0130] The voltage VCC is applied to the deskstation controller 211 whenthe portable computer 1 is in a power ON state, and the connectors 13and 26 are connected to each other. More specifically, when theconnectors 13 and 26 are connected to each other, the deskstationcontroller 211 can determine whether the portable computer 1 is in apower ON state by monitoring the voltage VCC.

[0131] The auto loading control mechanism 213 controls movement of thesecond connector unit 27 in accordance with a designation from thedeskstation controller 211. The attribute information of the deskstation2 and the like are stored in the EEPROM 212. The power supply unit 214is constituted by two power supply units PS1 and PS2 and controls powersupply to each unit of the deskstation 2 in accordance with thedocking/undocking operation of the portable computer 1 or the ON/OFFoperation of a power supply switch (P-SW2). The power supply switch(P-SW2) is a switch for receiving a designation of the ON/OFF operationof the main body of the portable computer 1 and the deskstation 2 whenthe portable computer 1 is docked with the deskstation 2. The powersupply switch (P-SW2) is arranged because the power supply switch(P-SW1) of the main body of the portable computer 1 cannot be physicallyoperated while the portable computer 1 is docked with the deskstation 2.Power supply voltages P1 (+5V and +12V) output from the power supplyunit PS1 are output in accordance with connection of an AC power supply.Power supply voltages P2 (3.3V, ±5V, and ±12V) output from the powersupply unit PS2 are set in a wait state until the expansion connector 28of the deskstation 2 is connected to the expansion connector 14 of theportable computer 1, even when the power supply switch (P-SW2) is turnedon.

[0132] The power supply voltages P1 are applied to the deskstationcontroller 211, the EEPROM 212, and the auto loading control mechanism213. On the other hand, the power supply voltages P2 are applied to theexpansion connectors 21 a and 21 b.

[0133] Various option cards 216 and 217 are connected to the expansionconnectors 21 a and 21 b. When the deskstation 2 is docked with theportable computer 1, i.e., when the expansion connectors 14 and 28 areconnected to each other, the expansion connectors 21 a and 21 b areconnected to the system bus 115 of the portable computer 1 through aninternal bus 218, the connectors 28 and 14, and the dock-control gatearray 125.

[0134]FIG. 4 is a block diagram showing the arrangement of the powersupply units PS1 and PD2. The power supply unit PS1 rectifies an ACpower supplied from the AC power supply into a DC power by a rectifier33 through a diode 31 for reverse-current prevention and a capacitor 32.The rectified DC power is converted into DC voltages of +5V and +12V bya DC/DC converter 34 and output. At this time, in the power supply unitPS1, voltage feedback control is performed by a switching circuit 35constituted by an FET (Field Effect Transistor), an SW controller 36, aphotoswitching circuit 37, and a feedback IC 38. With this operation,output voltages are maintained at predetermined levels. With the abovearrangement, the power supply unit PS1 outputs the voltages P1 inaccordance with connection of the deskstation 2 to the AC power supplyand the start of supply of the AC power.

[0135] The power supply unit PS2 receives an AC power through the diode31 and the capacitor 32 of the power supply unit PS1. The received ACpower is converted into a DC power by a rectifier 39 and supplied to aDC/DC converter 40 through a diode. The DC/DC converter 40 converts thereceived AC power into DC voltages of ±5V, +12V, and 3.3V and outputsthem. At this time, as in the power supply unit PS1, voltage feedbackcontrol is performed by a switching circuit 41, an SW controller 42, aphotoswitching circuit 43, and a feedback IC 44, thereby maintainingstable output of the DC voltages. A photoswitching circuit 45 turnedon/off in accordance with an RMTON signal sent from the deskstationcontroller 211 is arranged in the power supply unit PS2. The SWcontroller 42 controls the FET switching circuit 41 in accordance withthe ON/OFF operation of the photoswitching circuit 45.

[0136] With this operation, the power supply unit PS2 outputs/stops theoutput voltages P2 in accordance with the RMTON signal from thedeskstation controller 211. More specifically, even when the deskstation2 is connected to the AC power supply, and supply of the AC power isstarted, the voltages P2 are not output until the RMTON signal issupplied from the deskstation controller 211.

[0137]FIG. 5 is a circuit diagram showing the circuit arrangement in theperiphery of the deskstation controller 211.

[0138] The deskstation controller 211 generates control signals CNT andDIR for designating drive/stop of a motor (M) and the rotationaldirection of the motor (M), respectively, thereby controlling the autoloading control mechanism 213. As an interface between the deskstationcontroller 211 and the EEPROM 212, a serial interface constituted by aserial clock SCLK, a serial data input SIN, and a serial data outputSOUT are used, as shown in FIG. 5. In this case, in a data write mode,serial data of the serial data input SIN is written in the EEPROM 212 insynchronism with the serial clock SCLK in the order of addresses. In adata read mode, data is read out from the EEPROM 212 as the serial dataoutput SOUT in synchronism with the serial clock SCLK in the order ofaddresses.

[0139] The entire operation of docking the deskstation 2 with theportable computer 1 will be described below with reference to FIGS. 6Aand 6B.

[0140] In this computer system, three states are set, i.e., a releasestate in which the portable computer 1 is detached from the deskstation2; a set state in which the portable computer 1 is set at the mountingposition of the deskstation 2 while only the communication connectors 13and 26 are connected to each other; and a dock state in which theconnectors 13 and 26 are connected to each other while the expansionconnectors 14 and 28 are connected to each other by an auto loadingoperation.

[0141] When the portable computer 1 is to be docked with the deskstation2, the state is sequentially shifted in the order of the release state,the set state, and the dock state. This state shift is shown in FIG. 6A.The dock-control gate array 125 of the portable computer 1 is disabledwhen the portable computer 1 is not connected to the deskstation 2.

[0142] The main body of the portable computer 1 is fitted between theguide portions 23 and 24 of the deskstation 2 by the user, and the mainbody 1 is further pushed and set at the mounting position. At this time,the system is shifted from the release state to the set state.

[0143] In the set state, communication between the power supplycontroller 123 and the deskstation controller 211 is performed throughthe connectors 13 and 26. This communication is performed as 2-bitserial communication. The deskstation controller 211 outputs a dockrequest command in response to the ON operation of the switch SW1 (stepS11).

[0144] If the portable computer 1 is in a power ON state at the time ofshift from the release state to the set state, an SMI is issued inaccordance with setting of the dock request command. The CPU 111 issuesa dock power ON command to the power supply controller 123 in responseto the SMI (step S12). At this time, the dock-control gate array 125 isdisabled, so the system bus 115 is not connected to the expansionconnector 14. The power supply controller 123 outputs a dock startcommand to the deskstation controller 211 in response to the dock powerON command (step S13).

[0145] If the main body of the portable computer 1 is in a power OFFstate, the power supply controller 123 outputs a dock start command tothe deskstation controller 211 in accordance with the dock requestcommand (step S13).

[0146] Upon reception of the dock start command, the deskstationcontroller 211 performs docking (loading) processing, i.e., connectionprocessing of the expansion connector 14 and the connector 28 (stepS14). Thereafter, the deskstation controller 211 issues a dockcompletion command representing completion of the loading processing. Ifthe portable computer 1 is in a power ON state, the CPU 111 enables thedock-control gate array 125 in accordance with setting of the dockcompletion command. With this operation, the system bus 115 and theexpansion connector 14 are connected to each other. If the dockingprocessing is performed while the portable computer 1 is in a power ONstate, the deskstation controller 211 enables the power supply unit PS2,thereby applying the voltages P2 to the expansion connectors 21 a and 21b. With this operation, disadvantages caused by insertion/removal of alive line can be eliminated.

[0147] The docking operation will be described below in detail withreference to FIG. 6B as a flow chart showing the processing of the CPU111 of the portable computer main body 1, the power supply controller123, and the deskstation controller 211.

[0148] When the portable computer 1 is to be connected to thedeskstation 2, the main body of the portable computer 1 is fittedbetween the guide portions 23 and 24 of the deskstation 2 by the user,and the main body of the portable computer 1 is further pushed and setat the mounting position. With this operation, the system is shiftedfrom the release state to the set state. When the set state is set, thedetection switch SW1 is turned on. The deskstation controller 211detects the ON state of the switch SW1 (receives a pulse), therebyrecognizing that the portable computer 1 is set on the deskstation 2.

[0149] The deskstation controller 211 issues a dock request command inresponse to the ON operation of the detection switch SW1 (step A1). Thedock request command is issued to inquire the portable computer 1whether the set state can be changed to the dock state and set to thecommunication register of the deskstation interface 117 throughconnection between the connectors 26 and 13.

[0150] If the portable computer 1 is in a power ON state, thedeskstation interface 117 issues an SMI to the CPU 111 in accordancewith setting of the dock request command. With this operation, controlis shifted to a system BIOS. The system BIOS determines whether thecommand set in the deskstation interface 117 is a dock request command(step A3). Upon recognizing that the command set in the deskstationinterface 117 is a dock request command (YES in step A3), the systemBIOS informs the operating system that the docking operation of thedeskstation 2 is to be performed. If no dock request command is set (NOin step A3), the system BIOS performs other processing in the SMIprocessing.

[0151] If a change in system environment by connection of thedeskstation 2 does not pose any problem, the operating system informsthe system BIOS that the docking operation can be performed. The systemBIOS issues a dock power ON command in response to the information (stepA5). The dock power ON command is a command for permitting docking andsent to the power supply controller 123 through the communicationregister of the deskstation interface 117.

[0152] Upon reception of the dock power ON command, the power supplycontroller 123 issues a dock start command to the deskstation controller211 (steps A7 and A9). The dock start command is a permission responseto the dock request command and sent to the deskstation controller 211through the register of the deskstation interface 117.

[0153] If the portable computer 1 is in a power OFF state, the dockrequest command is sent to the power supply controller 123 through thedeskstation interface 117 (step A11). The power supply controller 123issues a dock start command to the deskstation controller 211 inresponse to the dock request command (step A13). If the dock requestcommand is received during a power OFF sequence, the power supplycontroller 123 issues the dock start command upon completion of thepower OFF sequence. The dock start command is sent to the deskstationcontroller 211 through the register of the deskstation interface 117.

[0154] Upon reception of the dock start command (step A15), thedeskstation controller 211 controls the auto loading control mechanism213 to execute a loading operation, thereby connecting the connector 28and the expansion connector 14 (step A17).

[0155] When the connectors 28 and 14 are connected to each other, i.e.,when docking is completed (YES in step A19), the detection switch SW2 isturned on. In response to the ON operation of the detection switch SW2,the deskstation controller 211 controls the auto loading controlmechanism 213 to stop the auto loading operation and at the same timeissues a dock completion command (step A21). The dock completion commandrepresents completion of docking between the portable computer 1 and thedeskstation 2 and set in the communication register of the deskstationinterface 117 through the connectors 26 and 13.

[0156] Thereafter, the deskstation controller 211 determines whether thevoltage VCC is applied from the portable computer 1 (step A23). Morespecifically the deskstation controller 211 determines thepresence/absence of application of the voltage VCC, thereby determiningwhether the portable computer 1 is in a power ON or OFF state. If thevoltage VCC is detected (YES in step A23), the deskstation controller211 outputs the RMTON signal to the power supply unit PS2 to enable thepower supply unit PS2 (step A25). If the voltage VCC is not detected (NOin step A23), other processing is performed.

[0157] The dock completion command issued in step A21 is set in thecommunication register of the deskstation interface 117 through theconnectors 13 and 26. If the portable computer 1 is in a power ON state,the deskstation interface 117 issues an SMI to the CPU 111 in responseto setting of the dock completion command. With this operation, controlis shifted to the system BIOS. The system BIOS determines whether thecommand set in the deskstation interface 117 is a dock completioncommand (step A27). Upon recognizing that the command set in thedeskstation interface 117 is a dock completion command (YES in stepA27), the dock-control gate array 125 is enabled (step A29). With thisoperation, the system bus 115 of the portable computer 1 and theinternal bus 218 of the deskstation 2 are connected to each other. Ifthe command set in the deskstation interface 117 is not a dockcompletion command (NO in step A27), other processing in the SMI routineis executed. The dock-control gate array 125 is controlled to be enabledafter the power supply unit PS2 is enabled, and the power supplyvoltages P2 are applied to the expansion connectors 21 a and 21 b.

[0158] If the portable computer 1 is in a power OFF state when the dockcompletion command issued in step A21 is set to the deskstationinterface 117, the command is sent to the power supply controller 123.The power supply controller 123 performs predetermined processing in thepower OFF state of the portable computer 1 without performing specialprocessing according to reception of the dock completion command (stepA31).

[0159] With the above processing, communication between the portablecomputer 1 and the deskstation 2 is performed before the portablecomputer 1 and the deskstation 2 is connected through the bus. When theuser sets the portable computer 1 in a power ON state on the deskstation2, the power supply unit PS2 and the dock-control gate array 125 areenabled such that docking between the expansion connectors 21 a and 21 bof the portable computer 1 and the deskstation 2 can be performed in apower ON state. With this operation, disadvantages such as an erroneousoperation of the portable computer 1 and destruction of the option cardof the deskstation 2 can be prevented. In addition, if the portablecomputer 1 in a power OFF state is set on the deskstation 2, theexpansion connector 14 and the connector 28 are connected to each otherwhile the power supply unit PS2 of the deskstation 2 is kept disabled.Therefore, when one of the portable computer 1 and the deskstation 2 isin a power ON state and the other is in a power OFF state, they are notconnected to each other. Only when both the portable computer 1 and thedeskstation 2 are in a power ON or OFF state, the expansion connector 14and the connector 28 are connected to each other.

[0160] If the docking operation of the portable computer 1 is completedin a power OFF state, the ON operation of the computer 1 and thedeskstation 2 is performed by operating the power supply switch (P-SW2)of the deskstation 2. Although two SMI routines are described in theprocessing routine of the CPU 111 in FIG. 6B, this description has beenmade to promote understanding of communication between the portablecomputer 1<and the deskstation 2. Only one routine is originally needed.

[0161] The procedures for the docking operation of the portable computer1 and the deskstation 2 have been described above. In undockingprocessing for detaching the portable computer 1 from the deskstation 2as well, the similar communication is executed between the portablecomputer 1 and the deskstation 2. In this case, the communication isperformed to prevent an erroneous operation of the portable computer 1when the portable computer 1 in a power ON state is detached from thedeskstation 2 (hot eject).

[0162] The undocking operation in which the portable computer 1 isdetached from the deskstation 2 will be described below with referenceto FIGS. 7A and 7B.

[0163] When the portable computer 1 is to be undocked from thedeskstation 2, the state is sequentially shifted in an order of the dockstate, the set state, and the release state. This state shift is shownin FIG. 7A.

[0164] In the dock state, when the eject switch SW3 provided to thedeskstation 2 is depressed by the user, the deskstation controller 211detects the ON operation of the switch SW3. The deskstation controller211 outputs an eject request command through the connectors 13 and 26(step S21).

[0165] If the portable computer 1 is in a power ON state, the CPU 111determines in accordance with the eject request command whether ejectprocessing can be executed. If communication with an external equipmentis being performed through a LAN (Local Area Network) or the like, theeject request command is ignored (ABORT). If the eject processing posesno problem, the CPU 111 disables the dock-control gate array 125 andthen sends an eject power OFF command to the power supply controller 123to permit a power OFF operation (step S21). The power supply controller123 issues an eject start command in accordance with this designation(step S22).

[0166] If the portable computer 1 is in a power OFF state, the ejectrequest command is sent to the power supply controller 123. The powersupply controller 123 outputs an eject start command to the deskstationcontroller 211 in accordance with the eject request command (step S22).

[0167] The deskstation controller 211 disables the power supply unit PS2in accordance with the eject start command and controls the auto loadingcontrol mechanism 213 to perform eject processing. With this processing,the expansion connectors 14 and 28 are disconnected from each other, andthe computer system is shifted from the dock state to the set state.With this operation, disadvantages caused by insertion/removal of a livecable can be eliminated.

[0168] The above-described undocking operation will be described indetail with reference to FIG. 7B as a flow chart showing the processingof the CPU 111 of the portable computer 1, the power supply controller123, and the deskstation controller 211.

[0169] When the eject switch SW3 provided to the deskstation 2 isdepressed by the user in the dock state, the deskstation controller 211detects the ON operation of the switch SW3 and issues an eject requestcommand to the portable computer 1 (step B1). The eject request commandis a command for informing the portable computer 1 that the eject switchSW3 is turned on, i.e., that the undocking operation is requested, andset in the communication register of the deskstation interface 117through connection between the connectors 26 and 13.

[0170] If the portable computer 1 is in a power ON state, thedeskstation interface 117 issues an SMI to the CPU 111 in response tosetting of the eject request command. With this operation, control isshifted to the system BIOS. The system BIOS determines whether thecommand set in the deskstation interface 117 is an eject request command(step B3). If the set command is an eject request command (YES in stepB3), configuration set processing is performed to determine whethereject processing can be executed (step B5). The configuration setprocessing will be described below.

[0171] The system BIOS issues an About-change Config message forinquiring a change in system configuration to the OS. Thereafter, the OSsends a message representing detachment (removal) of a device mounted inthe deskstation 2 to the device driver of this device mounted in thedeskstation 2. The device driver determines whether the device can bedetached. If YES, “OK” is returned to the OS. If any problem is posed,e.g., when LAN communication is being performed using a modem cardmounted in the deskstation 2, “Abort” is returned to the OS. If “OK” isreturned from the driver, the OS returns “OK” to the system BIOS. If“Abort” is returned from the driver, the OS displays a messagerepresenting that eject processing cannot be performed on the displayunit 12 by window writing display or the like.

[0172] If “Abort” is returned from the driver, the configuration setprocessing is finished after display processing, and no specialprocessing is performed any more (end). That is, if any problem isposed, and it is determined on the portable computer 1 side that ejectprocessing cannot be performed, the depressing operation of the ejectswitch SW3 is ignored.

[0173] If “OK” is received from the OS, i.e., if no problem is posedupon ejection of the deskstation 2, the system BIOS disables thedock-control gate array 125 (step B7). The system BIOS issues an ejectpermission command to the power supply controller 123 (step B9).

[0174] The eject permission command is a command representing that thedock-control gate array 125 is disabled, and the undocking operation ofthe deskstation 2 is permitted, and sent to the power supply controller123 through the communication register of the deskstation interface 117.

[0175] The power supply controller 123 issues an eject start command tothe deskstation controller 211 in accordance with the eject permissioncommand (steps B11 and B13). The eject start command is a permissionresponse to the eject request command and sent to the deskstationcontroller 211 through the register of the deskstation interface 117.

[0176] If the portable computer 1 is in a power OFF state, the ejectrequest command is sent to the power supply controller 123 by thedeskstation interface 117 (step B15). The power supply controller 123issues an eject start command to the deskstation controller 211 inresponse to the eject request command (step B17).

[0177] Upon reception of the eject start command, the deskstationcontroller 211 disables the power supply unit PS2 (steps B19 and B21).With this operation, the power supply voltages P2 applied to theexpansion connectors 21 a and 21 b are stopped. Thereafter, thedeskstation controller 211 controls the auto loading control mechanism213 to reversely rotate the motor, thereby disconnecting the expansionconnector 14 from the connector 28 (step B23). With this operation, thesystem is shifted from the dock state to the set state.

[0178] According to the above undocking method, generation of undockingis informed to the portable computer 1 before an actual undockingoperation of the portable computer 1 and the deskstation 2. If theportable computer 1 is in a power ON state, it is determined on thebasis of this information whether disadvantages are caused by theundocking operation. If it is disadvantageous, the switching operationfor undocking is ignored. If the undocking operation can be performed,the dock-control gate array 125 is disabled to electrically disconnectthe system bus 115 from the expansion connector 14. With this operation,an undocking operation can be prevented while the internal bus 218 ofthe deskstation 2 and the system bus 115 of the portable computer 1 areelectrically connected to each other. Thereafter, the power supply unitPS2 is disabled, and undocking processing of the expansion connectors 21a and 21 b is executed in a power OFF state. Therefore, an erroneousoperation of the portable computer 1 can be prevented. When theundocking operation is completed, the portable computer 1 is kept in thepower ON state, so that processing before the undocking operation of thedeskstation 2 can be continued. With the configuration set processing,an erroneous operation caused by a difference between the systemenvironment recognized by the operating system and the system BIOS andthe actual system environment can be prevented. Therefore, hot ejectionin which the portable computer 1 in a power ON state is detached fromthe deskstation 2 can be performed.

[0179] As described above, according to the first embodiment, connectionof the expansion connector of the expansion unit is informed to thecomputer main body before actual electrical connection with the systembus of the computer main body. For this reason, even when the userattaches the expansion unit to the computer main body in a power ONstate, disadvantages such as destruction of the expansion device such asthe option card of the expansion unit are prevented. Therefore,so-called hot docking can be performed. In addition, when the ejectswitch is turned on by the user, detachment of the expansion unit isinformed to the computer main body before the expansion connector of theexpansion unit is electrically disconnected from the system bus of thecomputer main body, and processing for electrically disconnecting theexpansion connector from the system bus is automatically executed. Forthis reason, hot undocking can be realized in which the user removes thecomputer main body in a power ON state from the expansion unit.

[0180] The second embodiment according to the present invention will bedescribed. A computer system according to the second embodiment isconstituted by a portable computer and a deskstation 2, as in the firstembodiment. They are connectable and substantially have outerappearances as shown in FIGS. 1 and 2. FIG. 8 is a block diagram showingthe configuration of a portable computer 1 and the deskstation 2according to the second embodiment. The same reference numerals denotethe same constituent elements as in the first embodiment, and a detaileddescription thereof will be omitted.

[0181] The second embodiment is different from the first embodiment intwo points. The first point is that the dock-control gate array 125 inthe first embodiment is not arranged. That is, a system bus 115 and anexpansion connector 14 are always connected to each other. The secondpoint is that a specific pin 13 p of a connector 13 is arranged in placeof the switch SW1 for detecting the set state and pulled up by a voltageVD output from a power supply 122 in the portable computer 1. In aconnector 26 of the deskstation 2, a pin 26 p corresponding to thespecific pin 13 p is grounded. When the connector 13 of the portablecomputer 1 is connected to the connector 26 of the deskstation 2, thespecific pin 13 p is grounded. Therefore, connection between theconnectors 13 and 26 can be detected with reference to the voltage VD.

[0182] A power supply unit 214 of the deskstation 2 has an arrangementshown in FIG. 4, as in the first embodiment. A deskstation controller211, an EEPROM 212, and an auto loading control mechanism 213substantially have a connection state as shown in FIG. 5. However, asdescribed above, the switch SW1 shown in FIG. 5 is omitted.

[0183] The overall operation of docking the deskstation 2 with theportable computer will be described below. In the system of the secondembodiment, as in the first embodiment, a release state in which theportable computer 1 is detached from the deskstation 2, a set state inwhich the portable computer 1 is set at the mounting position of thedeskstation 2 while only the communication connector 13 and theconnector 26 are connected to each other, and a dock state in which theconnectors 13 and 26 are connected to each other while the expansionconnectors 14 and 28 are connected to each other by an auto loadingoperation are available.

[0184] When the portable computer 1 is to be docked with the deskstation2, the state is sequentially shifted in an order of the release state,the set state, and the dock state. This state shift is almost the sameas that shown in FIG. 6A.

[0185] The main body of the portable computer 1 is fitted between guideportions 23 and 24 of the deskstation 2 by the user, and the main bodyis further pushed and set at the mounting position. At this time, thesystem is shifted from the release state to the set state.

[0186] In the set state, communication between a power supply controller123 and the deskstation controller 211 is performed through theconnectors 13 and 26. This communication is performed as 2-bit serialcommunication.

[0187] The power supply controller 123 monitors the voltage of thespecific pin 13 p and determines that the system is shifted from therelease state to the set state when the voltage of the specific pin 13 pbecomes 0V. This step corresponds to step S11 in FIG. 6A.

[0188] If the portable computer 1 is in a power ON state, a suspendrequest command is issued. A CPU 111 executes suspend processing inaccordance with the suspend request command. Thereafter, the CPU 111issues a dock power OFF command to the power supply controller 123. Thisstep corresponds to step S12 in FIG. 6A. The power supply controller 123performs power OFF processing of the portable computer 1 in response tothe dock power OFF command and outputs a dock start command to thedeskstation controller 211 (step S13).

[0189] If the portable computer 1 is in a power OFF state, the powersupply controller 123 outputs a dock start command to the deskstationcontroller 211 in accordance with the ground state of the specific pin13 p (step S13).

[0190] Upon reception of the dock start command, the deskstationcontroller 211 performs docking (loading) processing, i.e., connectionprocessing of the expansion connector 14 and the connector 28 (stepS14). Thereafter, the deskstation controller 211 issues a dockcompletion command representing completion of the loading processing. Ifthe portable computer 1 in a power ON state is shifted to the set state,the CPU 111 performs resume processing in accordance with setting of thedock completion command. With this processing, processing immediatelybefore the computer system is shifted to the set state is resumed. Thedeskstation controller 211 enables a power supply unit PS2 in accordancewith rising of a voltage VCC by power ON processing of the portablecomputer 1, thereby applying voltages P2 to expansion connectors 21 aand 21 b. With this operation, disadvantages caused by insertion/removalof a live cable can be eliminated.

[0191] The docking operation will be described below in detail withreference to FIG. 9 as a flow chart showing the processing of the CPU111 of the portable computer 1, the power supply controller 123, and thedeskstation controller 211.

[0192] When the portable computer 1 is to be connected to thedeskstation 2, the main body of the portable computer 1 is fittedbetween the guide portions 23 and 24 of the deskstation 2 by the user,and the main body of the portable computer 1 is further pushed and setat the mounting position with this operation, the system is shifted fromthe release state to the set state. When the set state is set, thespecific pin 13 p of the connector 13 is grounded. Upon detection of theground state of the specific pin 13 p, the power supply controller 123recognizes that the connector 13 is connected to the connector 26.

[0193] Thereafter, the power supply controller 123 determines whether apredetermined voltage, e.g., the voltage VCC is output from the powersupply 122, thereby determining whether the portable computer 1 is in apower ON or OFF state (step C1). If the portable computer 1 is in apower ON state (YES in step C1), the power supply controller 123 issuesa suspend request command (step C3). If the portable computer 1 is in apower OFF state (NO in step C1), a dock start command is issued (stepC5). The dock start command is sent to the deskstation controller 211through the connectors 13 and 26. If the ground state of the specificpin 13 p is detected during a power OFF sequence, the power supplycontroller 123 issues the dock start command after the power OFFsequence is ended.

[0194] The suspend request command issued in step C3 is set in apredetermined register of a deskstation interface 117. If the portablecomputer 1 is in a power ON state, the deskstation interface 117 issuesan SMI to the CPU 111 in accordance with setting of the suspend requestcommand.

[0195] In accordance with issue of the SMI, control is shifted to asystem BIOS. The system BIOS determines whether the command set in thedeskstation interface 117 is a suspend request command (step C7). If asuspend request command is set (YES in step C7), the operating system isinformed that docking with the deskstation 2 is to be performed.

[0196] If no problem is posed upon conversion of the system environmentby connection of deskstation 2, the operating system informs the systemBIOS that the docking operation can be performed (dock permission). Thesystem BIOS executes suspend processing in accordance with thisinformation (step C9).

[0197] More specifically, the system BIOS saves a system status (e.g.,the contents of the register of the CPU 111 or various I/O registers)necessary for resuming the operating system or an application programwhich is being executed in a main memory 113 and also stores a suspendflag representing a suspend state in the backed-up CMOS memory of areal-time clock 120, and a HOT-INS flag representing that the portablecomputer 1 is docked in a power ON state (hot insertion) in apredetermined memory of the deskstation interface 117. The system BIOSissues a dock power OFF command to the power supply controller 123 (stepC11). The dock power OFF command is a command for designating totemporarily power off the portable computer 1 for docking and set asuspend state and is sent to the portable computer 1 through thecommunication register of the deskstation interface 117.

[0198] Upon reception of the dock power OFF command, the power supplycontroller 123 controls the power supply 122 to execute the OFFoperation (steps C13 and C15). Thereafter, the power supply controller123 issues a dock start command to the deskstation controller 211 (stepC17). The dock start command is a permission response to the dockrequest command and sent to the deskstation controller 211 through theregister of the deskstation interface 117.

[0199] In step C7, if no suspend request command is set, the system BIOSperforms other processing in the SMI routine.

[0200] Upon reception of the dock start command, the deskstationcontroller 211 controls the auto loading control mechanism 213 toexecute an auto loading operation, thereby connecting the expansionconnector 14 to the connector 28 (steps C19 and C21). When the expansionconnector 14 and the connector 28 are connected to each other, i.e.,when the docking operation is completed (YES in steps C23), a detectionswitch SW2 is turned on. In response to the ON operation of thedetection switch SW2, the deskstation controller 211 controls the autoloading control mechanism 213 to stop the auto loading operation andissues a dock completion command (step C25). The dock completion commandrepresents completion of docking between the portable computer 1 and thedeskstation 2 and is set to the communication register of thedeskstation interface 117 through connection between the connectors 26and 13.

[0201] At this time, the portable computer 1 is in a power OFF state, sothat the dock completion command is received by the power supplycontroller 123 (step C27). The power supply controller 123 determineswhether the HOT-INS flag is set (step C29). If YES, the power supply 122is controlled to perform power ON processing of the portable computer 1(step. C31). This processing is performed to power on the portablecomputer 1 again, which is temporarily powered off because the computersystem is shifted to the set state while the main body of the portablecomputer 1 is kept in a power ON state.

[0202] In response to the power ON processing, the CPU 111 executes thesystem BIOS. The system BIOS checks whether the system is in a suspendstate with reference to the suspend flag and executes resume processingif a suspend state is detected (step C33). In the resume processing, thesystem BIOS restores the contents saved in the main memory 113 to theoriginal positions, thereby restoring the system to the stateimmediately before the power OFF operation. In addition, the HOT-INSflag set in step C9 is reset. Thereafter, the system BIOS confirms thatthe deskstation 2 is attached to the expansion connector 14 of theportable computer 1 and informs it to the operating system. Theoperating system or the system BIOS detects the type of the connectedoption card from the information-stored in the EEPROM 212 of thedeskstation 2, thereby reconfiguring the system environment into anenvironment for allowing the use of the option card (step C35).

[0203] If the system is not in a suspend state, the system BIOS executesan IRT routine to check the system configuration as in a normaloperation, thereby recognizing the presence of the deskstation 2. Afterthe operating system is bootstrapped, the system BIOS informs theoperating system of the presence of the deskstation 2. Thereafter, theoperating system or the system BIOS detects the type of the connectedoption card from the information stored in the EEPROM 212 of thedeskstation 2, thereby reconfiguring the system environment into anenvironment for allowing the use of the option card.

[0204] The deskstation controller 211 of the deskstation 2 outputs anRMTON signal to the power supply unit PS2 in accordance with rising ofthe voltage VCC applied according to the power ON operation of theportable computer 1 (step C37). The power supply unit PS2 outputs thevoltages PS2 in accordance with the RMTON signal. With this operation,both the portable computer 1 and the deskstation 2 are set in a power ONstate.

[0205] With the above processing, generation of docking is informed tothe operating system of the portable computer 1 before the portablecomputer 1 and the deskstation 2 are connected through the bus while theportable computer 1 is in a power ON state. If the docking operation canbe performed, the power OFF operation of the portable computer 1 isautomatically executed. No power supply voltage is applied to theexpansion connectors 21 a and 21 b of the deskstation 2 until theportable computer 1 is powered on. For this reason, even when the usersets the computer 1 in a power ON state on the deskstation 2,disadvantages such as an erroneous operation of the portable computer 1and destruction of the option card of the deskstation 2 can be preventedbecause the portable computer 1 can be docked with the expansionconnectors 21 a and 21 b of the deskstation 2 in a power OFF state. Ifthe portable computer 1 in a power ON state is set, the portablecomputer 1 is automatically powered on upon completion of the dockingoperation, thereby reconfiguring the system environment for allowing theuse of the option card. Therefore, hot docking can be realized in whichthe portable computer 1 kept in a power ON state is docked with thedeskstation 2.

[0206] The power ON operation of the docked computer 1 may be manuallyperformed by the user. In this case, the portable computer 1 and thedeskstation 2 are powered on by operating a power supply switch P-SW2 ofthe deskstation 2.

[0207] The procedures for docking the portable computer 1 with thedeskstation 2 have been described above. In undocking processing fordetaching the portable computer 1 from the deskstation 2 as well, thesimilar communication is executed between the portable computer 1 andthe deskstation 2. In this case, the communication is performed toprevent an erroneous operation of the portable computer 1 when theportable computer 1 in a power ON state is detached from the deskstation2 (hot eject).

[0208] The undocking operation in which the portable computer 1 isdetached from the deskstation 2 will be described below.

[0209] When the portable computer 1 is to be undocked from thedeskstation 2, the state is sequentially shifted in an order of the dockstate, the set state, and the release state. This state shift is almostthe same as that shown in FIG. 7A.

[0210] In the dock state, when an eject switch SW3 provided to thedeskstation 2 is depressed by the user, the deskstation controller 211detects the ON operation of the switch SW3. The deskstation controller211 outputs an eject request command through the connectors 13 and 26(step S21).

[0211] If the portable computer 1 is in a power ON state, the CPU 111determines in accordance with the eject request command whether powerOFF processing for ejection, which includes suspend processing, can beperformed on the deskstation 2 side. If communication with an externalequipment is being performed through a LAN (Local Area Network) or thelike, the eject request command is ignored (ABORT). If the power OFFprocessing for ejection poses no problem, the CPU 111 performspredetermined processing including suspend processing and then sends aneject power OFF command to the power supply controller 123 to permit apower OFF operation (step S21). The power supply controller 123 performsthe power OFF processing of the portable computer 1 and issues an ejectstart command in accordance with this designation (step S22).

[0212] If the portable computer 1 is in a power OFF state, the ejectrequest command is sent to the power supply controller 123. The powersupply controller 123 outputs an eject start command to the deskstationcontroller 211 in accordance with the eject request command (step S22).

[0213] The deskstation controller 211 disables the power supply unit PS2in accordance with the eject start command and controls the auto loadingcontrol mechanism 213 to perform eject processing. With this processing,the expansion connector 14 and the connector 28 are disconnected fromeach other, and the computer system is shifted from the dock state tothe set state. With this operation, the expansion connector 14 and theconnector 28 can be disconnected from each other while keepingelectrical connection, and disadvantages caused by insertion/removal ofa live cable can be eliminated.

[0214] The above-described undocking operation will be described belowin detail with reference to FIG. 10 as a flow chart showing theprocessing of the CPU 111 of the portable computer 1, the power supplycontroller 123, and the deskstation controller 211.

[0215] When the eject switch SW3 provided to the deskstation 2 isdepressed by the user in the dock state, the deskstation 2 detects theON operation of the switch SW3 and issues an eject request command tothe portable computer 1 (step D1). The eject request command is acommand for informing the portable computer 1 that the eject switch SW3is turned on, i.e., that the undocking operation is requested, and setin the communication register of the deskstation interface 117 throughconnection between the connectors 26 and 13.

[0216] If the portable computer 1 is in a power ON state, thedeskstation interface 117 issues an SMI to the CPU 111 in response tosetting of the eject request command. With this operation, control isshifted to the system BIOS. The system BIOS recognizes whether thecommand set in the deskstation interface 117 is an eject request command(YES in step D3). Upon recognition of setting of an eject requestcommand, the following processing is performed (step D5).

[0217] The system BIOS informs the operating system that an ejectingoperation is to be performed. The operating system informs the systemBIOS of eject permission when no problem is posed upon ejection of thedeskstation 2. If communication with an option card is being executedand cannot be interrupted, the eject request is rejected by theoperating system and aborted. The portable computer 1 informs theoperator that the eject request is aborted by window display or thelike. In addition, after the eject request is aborted, the CPU 111, thepower supply controller 123, and the deskstation controller 211 do notperform special processing.

[0218] When the ejecting operation is permitted by the operating system,the system BIOS executes suspend processing.

[0219] More specifically, the system BIOS saves a system status (e.g.,the contents of the register of the CPU 111 and various I/O-registers)necessary for resuming the operating system or an application programwhich is being executed in the main memory 113 and also stores a suspendflag representing a suspend state for undocking in the CMOS memory ofthe real-time clock 120. The system BIOS issues an eject power ONcommand to the power supply controller 123 (step D7).

[0220] The eject power OFF command is a command for designating totemporarily power off the portable computer 1 for undocking and is sentto the power supply controller 123 through the communication register ofthe deskstation interface 117.

[0221] Upon reception of the eject power OFF command, the power supplycontroller 123 controls the power supply 122 to execute power OFFprocessing (steps D9 and D11).

[0222] Thereafter, the power supply controller 123 issues an eject startcommand to the deskstation controller 211 (step D18). The eject startcommand is sent to the deskstation controller 211 through the registerof the deskstation interface 117.

[0223] If the portable computer 1 is in a power OFF state, the ejectrequest command is sent to the power supply controller 123 (step D15).The power supply controller 123 issues an eject start command to thedeskstation controller 211 in response to the eject request command(step D17).

[0224] Upon reception of the eject start command, the deskstationcontroller 211 outputs the RMTON signal to the power supply unit PS2(steps D19 and D21). With this operation, the power supply unit PS2 isdisabled to stop the voltages P2 applied to the expansion connectors 21a and 21 b. Thereafter, the deskstation controller 211 controls the autoloading control mechanism 213 to reversely rotate the motor, therebydisconnecting the expansion connector 14 from the connector 28 (stepD23). With this operation, the system is shifted from the dock state tothe set state.

[0225] According to the above undocking processing, generation ofundocking is informed to the operating system of the portable computer 1before actual undocking of the portable computer 1 and the deskstation2. If the portable computer 1 is in a power ON state, generation ofundocking is informed to the CPU 111. If the undocking operation can beperformed, the power OFF operation of the computer 1 is automaticallyexecuted. Application of the power supply voltages to the expansionconnectors 21 a and 21 b of the deskstation 2 is stopped in response tothe power OFF operation of the computer 1. For this reason, the portablecomputer 1 can be normally undocked from the expansion connectors 21 aand 21 b of the deskstation 2 in a power OFF state, thereby preventingan erroneous operation of the portable computer 1. In this manner, adesignation operation for detaching the portable computer 1 in a powerON state from the deskstation 2 can be performed.

[0226] The power ON operation of the portable computer 1 after theejecting operation may be manually performed by the user orautomatically performed upon completion of the ejecting operation. Theuser may select a mode to designate whether the computer 1 isautomatically powered on upon after the ejecting operation. Instead ofpulling up the specific pin 13 p, a predetermined pin of the connector26 on the deskstation 2 side may be pulled up. Alternatively, the switchSW1 shown in the first embodiment may be provided.

[0227] When the computer system is configured such that the portablecomputer 1 is powered on after the portable computer 1 is undocked fromthe deskstation 2, the deskstation controller 211 issues an ejectcompletion command representing completion of the undocking operation ofthe portable computer 1 and the deskstation 2 upon completion of ejectprocessing. More specifically, the deskstation controller 211 issues aneject completion command, and the eject completion command is set in thecommunication register of the deskstation interface 117 throughconnection between the connectors 26 and 13.

[0228] At this time, the portable computer 1 is in a power OFF state, sothat the eject completion command is received by the power supplycontroller 123, and the portable computer 1 is powered on again.

[0229] In response to the power ON operation, the system BIOS isexecuted by the CPU 111. The system BIOS checks whether the system is ina suspend state with reference to the suspend flag and executes resumeprocessing if a suspend state is detected. In the resume processing, thesystem BIOS restores the contents saved in the main memory 113 to theoriginal positions, thereby restoring the system to the stateimmediately before the power OFF operation. Thereafter, the system BIOSconfirms that the deskstation 2 is not attached to the expansionconnector 14 of the portable computer 1 and informs it to the operatingsystem. Thereafter, the operating system or the system BIOS reconfiguresthe system environment into an environment excluding the option card.

[0230] If the system is not in a suspend state, the system BIOS executesan IRT routine to check the system configuration as in a normaloperation, thereby recognizing the absence of the deskstation 2. Theoperating system is then bootstrapped.

[0231] When an ejecting operation is designated to the operator, i.e.,when the eject switch SW3 is operated, and the portable computer 1 is ina power ON state, a flag may be set. In accordance withsetting/resetting of the flag, the power ON/OFF operation of theportable computer 1 may be controlled upon completion of ejectprocessing.

[0232] As described above, according to the present invention,connection of the expansion connector of the expansion unit is informedto the computer main body before actual electrical connection with thesystem bus of the computer main body, and processing such as the powerOFF operation of the computer main body is automatically executed. Forthis reason, even when the user attaches the expansion unit to thecomputer main body in a power ON state, disadvantages such asdestruction of the expansion device such as an option card of theexpansion unit are prevented. Therefore, so-called hot docking can beperformed. In addition, when the eject switch is operated by the user,detachment of the expansion unit is informed to the computer main bodybefore the expansion connector of the expansion unit is electricallydisconnected from the system bus of the computer main body, andprocessing such as the power OFF operation of the computer main body isautomatically executed. For this reason, hot undocking can be realizedin which the user detaches the computer main body in a power ON statefrom the expansion unit.

[0233] The third embodiment of the present invention will be describedbelow.

[0234]FIG. 11 is a block diagram showing a computer system according tothe third embodiment, which is constituted by a portable computer and afunction expansion device (expansion unit).

[0235]FIG. 11 shows a portable computer 4, an expansion unit main body(DS) 5, and a power supply unit 6. The expansion unit main body (DS) 5is connected to the power supply unit (PS UNIT) 6 through a cable 50with a predetermined length and receives a plurality of (three) DC powersupply voltages from the power supply unit (PS UNIT) 6 through the cable50.

[0236] A portable computer mounting portion 51 where the portablecomputer (PC) 4 is slid back and forth to be attached or detached isarranged at the upper portion of the expansion unit main body (DS) 5.Chassis storage portions (USLT-A and USLT-B) 53A and 53B for storingregular-sized universal chassis (UCH) 52A and 52B each having a loadedI/O equipment are arranged at the front portion of the expansion unitmain body (DS) 5.

[0237] The portable computer 4 can be mounted on the expansion unit mainbody (DS) 5. When the rear surface portion of the portable computer 4 isslid and inserted to the portable computer mounting portion 51 of theexpansion unit main body (DS) 5 in a predetermined amount, an expansionconnector (receptacle) (CNa in FIG. 13) provided to the rear surfaceportion is coupled to a connector (CNn in FIG. 13) provided to theexpansion unit main body (DS) 5 in correspondence with the aboveconnector, thereby circuit-connecting the portable computer (PC) 4 tothe expansion unit main body (DS) 5.

[0238] As shown in FIG. 13, the portable computer (PC) 4 has lockengagement mechanisms (lock-grooves) 46 a and 46 b which are engaged ordisengaged by the expansion unit main body (DS) 5.

[0239] The power supply unit (PS UNIT) 6 applies power supply voltagesto the expansion unit main body (DS) 5. In this embodiment, three DCpower supply voltages (+5V, +12V, and +15V) are generated in accordancewith a designation from the expansion unit main body (DS) 5 through thecable 50 and supplies the power to the portable computer (PC) 5. Asshown in FIG. 12, the power supply unit (PS UNIT) 6 has a plurality of(three) power supply (AC) outlets PC1 to PC3 which are ON/OFF-controlledwith predetermined time lags. A power supply unit for generating thethree power supply voltages and a function circuit including a powersupply control microprocessor are arranged in the power supply unit (PSUNIT) 6.

[0240] The cable 50 is constituted by a plurality of power supply linesfor connecting the expansion unit main body (DS) 5 to the power supplyunit (PS UNIT) 6 and applying the three DC power supply voltagesgenerated by the power supply unit (PS UNIT) 6 to the expansion unitmain body (DS) 5, and a single control signal line for supplying, to thepower supply unit (PS UNIT) 6, a power supply control signal fordesignating the ON/OFF operation of the power supply voltage generatedby the expansion unit main body (DS) 5.

[0241] The regular-sized universal chassis (UCH) 52A and 52B are used toload (connect) IO equipments in the expansion unit main body (DS) 5 andequalize the sizes of the IO equipments loaded in the expansion unitmain body (DS) 5. In this embodiment, as the IO equipments mounted inthe expansion unit main body (DS) 5, a CD-ROM is mounted on theuniversal chassis (UCH) 52A while a hard disk drive (HDD) is mounted onthe universal chassis (UCH) 52B. In this case, the IO equipments such asthe CD-ROM and the HDD are adjusted to predetermined positions in thechassis by a plurality of screws (B, . . . ) such that the connectorcoupling positions are matched, and fixed on the chassis.

[0242] When the universal chassis (UCH) 52A and 52B incorporating the IOequipments are respectively inserted in the chassis storage portions(USLT-A and USLT-B) 53A and 53B provided to the expansion unit main body(DS) 5 by a predetermined amount, the IO equipments mounted on thechassis are coupled through connectors and form circuits with theexpansion unit main body (DS) 5. With this arrangement, when an optionunit such as a hard disk unit is to be mounted, mounting and exchange ofoption units can be easily performed without using a tool such as adriver.

[0243]FIG. 12 is a block diagram showing the internal arrangement of thepower supply unit (PS UNIT) 6 shown in FIG. 11.

[0244] Referring to FIG. 12, a power supply control microprocessor(PS-CPU) 61 controls the entire power supply unit. The power supplycontrol microprocessor (PS-CPU) 61 receives a power supply controlsignal for designating the ON/OFF operation of the power supply from theexpansion unit main body (DS) 5 through the cable 50 and an IO port(IOP) 62. Upon reception of designation of the power ON operation, themicroprocessor 61 starts operating a power supply (PS) 63 for generatingthree DC power supply voltages (+5V, +12V, and +15V) required by theexpansion unit main body (DS) 5. In this embodiment, while an AC plug isinserted, the power supply control microprocessor (PS-CPU) 61 alwaysreceives an operating power supply voltage and is set in an operable(sleep) state. When a power supply control signal for designating theON/OFF operation of the power supply is received as an interrupt signal,a normal operative mode is set to execute power supply controlprocessing. More specifically, upon reception of a power supply controlsignal through the IO port (IOP) 62, the power supply controlmicroprocessor (PS-CPU) 61 executes power OFF processing if the systemis in a power ON state or power ON processing if the system is power OFFstate.

[0245] The IO port (IOP) 62 transmits a control signal between themicroprocessor (PS-CPU) 61 and the control unit (microprocessor) of theexpansion unit main body (DS) 5. The IO port (IOP) 62 receives a powersupply control signal for designating the ON/OFF operation of the powersupply from the expansion unit main body (DS) 5 through the controlsignal line of the cable 50 and informs the contents of the signal tothe microprocessor (PS-CPU) 61. In this embodiment, to simplify thearrangement, the control signal line of the cable 50 is always pulledup. Every time the power supply control signal on the line goes to aground level (“0”) for a predetermined period of time (e.g., 0.5 sec), apower supply control signal for designating the ON/OFF operation of thepower supply is supplied to the power supply control microprocessor(PS-CPU) 61. Upon reception of the power supply control signal, thepower supply control microprocessor (PS-CPU) 61 executes power OFFprocessing if the system is in a power ON state or power ON processingif the system is in a power OFF state.

[0246] The power supply (PS) 63 is a power supply circuit as a mainconstituent element of the power supply unit (PS UNIT) 6. The powersupply (PS) 63 generates three DC power supply voltages (+5V, +12V, and+15V) required by the expansion unit main body (DS) 5 under control ofthe power supply control microprocessor (PS-CPU) 61 and sends thevoltages to the power supply lines of the cable 50.

[0247] A driver (DRV) 64 has a sequence controller forON/OFF-controlling the power supply (AC) outlets PC1 to PC3, whichON/OFF-controls feed switches S1 to S3 at different timings (T1 to T3)with predetermined time lags under the control of the power supplycontrol microprocessor (PS-CPU) 61 and sequentially controls the ON/OFFoperation of the AC power supplies (commercial AC power supplies) of thepower supply (AC) outlets PC1 to PC3 at the predetermined differenttimings (T1 to T3).

[0248] With the sequence control of the power supply (AC) outlets PC1 toPC3, a power ON/OFF sequence mechanism according to the systemconfiguration can be easily realized. Disadvantages such as variationsin voltage or breaker down caused by rapid power consumption due to rushcan be prevented, thereby ensuring a stable operation. Additionally, therated power of each equipment or line member can be suppressed tosimplify the system.

[0249]FIG. 13 is a block diagram showing part of the function circuit inthe expansion unit main body (DS) 5 shown in FIG. 11 and the lockmechanism of the portable computer.

[0250] Referring to FIG. 13, a lock mechanism 54 is driven to fix theportable computer (PC) 4 to the expansion unit main body (DS) 5 when theportable computer (PC) 4 is set at a predetermined position of theportable computer mounting portion 51 provided to the expansion unitmain body (DS) 5.

[0251] The lock mechanism 54 has a lock lever p which is arranged at apredetermined position of the slide surface of the portable computermounting portion and pivotally set at lying and rising positions. Whenthe portable computer (PC) 4 is not set, the lock lever p is at thelying position to match the slide surface. When the portable computer(PC) 4 is set, the lock lever p rises to project from the slide surfaceand is engaged with the lock engagement mechanism (to be referred to asa lock groove) 46 a (or 46 b) provided at a predetermined position ofthe bottom surface of the portable computer (PC) 4, thereby stationarilyholding the portable computer (PC) 4 at a predetermined position.

[0252] A driving unit (DRV) 55 controls the lying/rising operation ofthe lock lever p of the lock mechanism 54. The driving unit (DRV) 55drives, e.g., an electromagnetic plunger under the control of a controlunit 56 to raise/lay the lock lever p, thereby engaging (locking) thelock lever p with the lock groove 46 a (or 46 b) or disengaging(releasing) them.

[0253] The control unit (CNT) 56 is constituted by a microprocessor forcontrolling the expansion unit main body (DS) 5. The control unit 56sends a power supply control signal (SWP), supplied upon operation of apower supply control key 57, for designating the ON/OFF operation of thepower supply to the power supply unit (PS) 6 through the power supplycontrol line of the cable 50, and supplies the above three DC powersupply voltages (PV) received from the power supply unit (PS) 6 to aninternal circuit. In this-embodiment, when the power supply control key57 is operated, the power supply control line pulled up on the powersupply unit (PS UNIT) 6 side is shorted to a ground line, therebyoutputting the power supply control signal (SWP) for designating theON/OFF operation of the power supply.

[0254] The control unit 56 recognizes in accordance with a switch signal(to be described later) that the portable computer (PC) 4 is set at apredetermined position of the mounting portion 51 and performs controlsuch that the driving unit (DRV) 55 is driven to operate the lockmechanism 54, thereby stationarily holding the portable computer (PC) 4at a predetermined position of the mounting portion 51. With this lockmechanism, disadvantages such as data destruction caused by a releasingoperation during the operation can be prevented. At the same time, theportable computer (PC) 4 is integrated with the expansion unit main body(DS) 5, thereby obtaining an effect for security.

[0255] The power supply control key (KP) 57 is used to designate theON/OFF operation of the power supply of the expansion unit main body(DS) 5 and feed/stop of the power supply (AC) outlets PC1 to PC3provided to the power supply unit-(PS UNIT) 6. In this embodiment, as asimplest arrangement, the power supply control line pulled up on thepower supply unit (PS UNIT) 6 side is shorted to the ground line byoperating a key, and a power supply control signal on the power supplycontrol line is set at a ground (“0”) level. However, for example, whena keypad having a plurality of numeric keys is used, and a key codeinput by operating the keys of the keypad is input to the control unit56, the ON/OFF operation of the power supply of the expansion unit andfeed/stop of the power supply (AC) outlets PC1 to PC3 can beindividually designated. When these designations are made valid bycombining specific keys, a security function can also be obtained. Inthis case, however, a circuit for operating the control unit 56 in asleep mode is necessary.

[0256] A status detection switch 58 is used to detect that the portablecomputer (PC) 4 is set at a predetermined position of the portablecomputer mounting portion 51 and informs the detection state to thecontrol unit 56.

[0257] A power supply (PV) 59 is incorporated in the expansion unit mainbody (DS) 5 and supplies the above three DC power supply voltages (PV)received from the power supply unit 6 through the cable 50 to theinternal circuit including the connector (CNb) under the control of thecontrol unit 56.

[0258]FIG. 14 is a view showing a connection example of the portablecomputer (PC) 4 mounted in the expansion unit main body (DS) 5 through aport replicator.

[0259] Referring to FIG. 14, a port replicator 7 is connected betweenthe portable computer (PC) 4 and the expansion unit main body (DS) 5through connectors. In the use of the port replicator 7, when the locklever p of the lock mechanism 54 rises, the lock lever p is engaged withthe lock groove 46 b of the lock engagement mechanisms (lock grooves) 46a and 46 b provided at predetermined positions of the bottom surface ofthe portable computer (PC) 4, thereby stationarily holding the portablecomputer (PC) 4 at a predetermined position.

[0260] With such a port replicator structure, when the portable computer(PC) 4 is mounted on the expansion unit main body (DS) 5, each I/O portsuch as a printer connection port, a serial (RS-232C) port, or a CRT (R,G, and B) connection port, which is closed by a connection between theportable computer (PC) 4 and the expansion unit main body (DS) 5, can beeasily used, thereby easily connecting arbitrary option equipments.

[0261] The operation of the third embodiment of the present inventionwill be described below with reference to FIGS. 11 to 14.

[0262] The function expansion device (expansion unit) according to thisembodiment has a power supply unit constituted in a housing independentof the expansion unit main body, and the power supply unit and theexpansion unit main body are connected by a cable. With thisarrangement, when the expansion unit main body (DS) 5 is set on a desk,and the power supply unit (PS UNIT) 6 is placed under the desk (on thefloor), the space can be effectively used. In addition, since theexpansion unit main body (DS) 5 does not include a power supplymechanism which generates heat or noise, a compact and light expansionunit can be realized. With this arrangement, easy handling and a stableoperation with a high reliability can be maintained.

[0263] In the above embodiment, when the expansion unit is to be used,the portable computer (PC) 4 is mounted at a predetermined position ofthe mounting portion 51 provided to the expansion unit main body (DS) 5by a slide operation, and the power supply control key 57 is operated.

[0264] The power supply control signal (SWP), input by operating thepower supply control key 57, for designating the ON/OFF operation of thepower supply is supplied to the control unit 56.

[0265] The control unit 56 sends the power supply control signal (SWP)supplied upon operation of the power supply control key 57 to the powersupply unit (PS UNIT) 6 through the power supply control line of thecable 50. More specifically, in this embodiment, the power supplycontrol signal on the power supply control line of the cable 50 isswitched from “1” (pull-up state) to “0” (ground state) in accordancewith the ON operation of the power supply control key 57.

[0266] The power supply control signal on the power supply control lineof the cable 50 is received by the IO port (IOP) 62 of the power supplyunit (PS UNIT) 6.

[0267] When the power supply control signal on the power supply controlline goes to the ground level (“0”) for a predetermined period of time(e.g., 0.5 sec), the IO port (IOP) 62 supplies the power supply controlsignal for designating the ON/OFF operation of the power supply to thepower supply control microprocessor (PS-CPU) 61.

[0268] Upon reception of the power supply control signal from the IOport (IOP) 62, the power supply control microprocessor (PS-CPU) 61executes power OFF processing if the system is in a power ON state, orpower ON processing if the system is in a power OFF state. In the powerON processing, the power supply (PS) 63 is started, and the driver (DRV)64 is also started.

[0269] The power supply (PS) 63 generates three DC power supply voltages(+5V, +12V, and +15V) required by the expansion unit main body (DS) 5under the control of the power supply control microprocessor (PS-CPU) 61and sends these voltages to the power supply lines of the cable 50.

[0270] The driver (DRV) 64 turns on the feed switches S1 to S3 at thedifferent timings (T1 to T3) with predetermined time lags under thecontrol of the power supply control microprocessor (PS-CPU) 61, andsequentially supplies the AC power supply voltages (commercial AC powersupply voltages=AC) of the power supply (AC) outlets PC1 to PC3 at thepredetermined different timings (T1 to T3).

[0271] The three DC power supply voltages (+5V, +12V, and +15V) outputfrom the power supply (PS) 63 are supplied to the power supply (PS) 59of the expansion unit main body (DS) 5 through the power supply lines ofthe cable 50 so as to serve as the operating power supply voltages (PV).

[0272] When the operating power supply voltages (PV) are supplied, and adetection signal for informing that the portable computer (PC) 4 is setat a predetermined position is received from the status detection switch58, the control unit 56 of the expansion unit main body (DS) 5 startsoperating the driving unit (DRV) 55 to drive the lock mechanism 54,thereby raising the lock lever p of the lock mechanism 54. The locklever p is engaged with the lock engagement mechanism (lock groove) 46 aof the portable computer (PC) 4, thereby stationarily holding theportable computer (PC) 4 at a predetermined position of the portablecomputer mounting portion 51.

[0273] The control unit 56 controls the power supply (PS) 59 todistribute and supply the operating power supply voltages (PV) receivedthrough the cable 50 to predetermined circuits including connectors in apredetermined order.

[0274] With this operation, the connection equipments including theportable computer (PC) 4 mounted in the expansion unit main body (DS) 5,and the I/O equipments on the universal chassis (UCH) 52A and 52B storedin the chassis storage portions (USLT-A and USLT-B) 53A and 53B (in thisembodiment, the CD-ROM mounted on the universal chassis (UCH) 52A andthe hard disk drive (HDD) mounted on the universal chassis (UCH) 52B)are started by power ON control according to a predetermined powersupply sequence.

[0275] When the system operation is to be finished, the power supplycontrol key 57 of the expansion unit main body (DS) 5 is operated. Thepower supply control signal (SWP) according to the operation of thepower supply control key 57 is sent to the power supply unit (PS UNIT) 6through the power supply control line of the cable 50, as in the aboveoperation, and received by the power supply control microprocessor(PS-CPU) 61 through the IO port (IOP) 62 of the power supply unit (PSUNIT) 6.

[0276] When the power supply control signal (ground level=“0”) fordesignating the ON/OFF operation of the power supply is received in apower ON state, the power supply control microprocessor (PS-CPU) 61executes power OFF processing. The power supply (PS) 63 and the driver(DRV) 64 are started to stop the operating power supply voltages for theexpansion unit main body (DS) 5 in a predetermined order and also stopfeeding to the power supply (AC) outlets PC1 to PC3 in a predeterminedorder.

[0277] As described above, in the function expansion unit (expansionunit) having the above arrangement according to the embodiment of thepresent invention, the expansion unit has a power supply unitconstituted in a housing independent of the expansion unit main body,and they are connected by a cable. For this reason, when the expansionunit main body (DS) 5 is set on a desk, and the power supply unit (PSUNIT) 6 is placed under the desk (on the floor), the space can beeffectively used. In addition, since the expansion unit main body (DS) 5does not include a power supply mechanism which generates heat or noise,a compact and light expansion unit can be realized. With thisarrangement, easy handling and a stable operation with a highreliability can be maintained.

[0278] With the power ON/OFF sequence control function of the expansionunit main body (DS) 5 and the feed/stop sequence control function of thepower supply (AC) outlets PC1 to PC3, the power ON/OFF operationaccording to the start/end of operation of the entire system can befacilitated, thereby largely decreasing the work load. At the same time,an erroneous operation caused by a shift of power supply states can beprevented.

[0279] Since the expansion unit main body (DS) 5 has the lock mechanism54 for the mounted portable computer (PC) 4, disadvantages such as datadestruction caused by a releasing operation during the operation can beprevented. At the same time, the portable computer (PC) 4 is integratedwith the expansion unit main body (DS) 5, thereby obtaining an effectfor security.

[0280] When the universal chassis (UCH) 52A and 52B incorporating the IOequipments are inserted in the chassis storage portions (USLT-A andUSLT-B) 53A and 53B provided to the expansion unit main body (DS) 5 by apredetermined amount, the IO equipments mounted on the chassis arecoupled through connectors and form circuits with the expansion unitmain body (DS) 5. With this arrangement, when an option unit such as ahard disk unit is to be mounted, mounting and exchange of variousarbitrary option units can be easily performed without using a tool suchas a driver.

[0281] With the arrangement in which the feed/stop operations of thepower supply (AC) outlets PC1 to PC3 are sequentially controlled at thepredetermined different timings (T1 to T3), a power ON/OFF sequencemechanism according to the system configuration can be easily realized.Disadvantages such as variations in voltage or breaker down caused byrapid power consumption due to rush can be prevented, thereby ensuring astable operation. Additionally, the rated power of each equipment orline member can be suppressed to simplify the system.

[0282] In the above embodiment, the power ON operation of the expansionunit is designated by operating the power supply control key (KP) 57.However, as another embodiment, the control unit 56 may designate thepower ON operation of the expansion unit main body (DS) 5 on the basisof a detection signal from the status detection switch 58.

[0283] In this case, when the portable computer (PC) 4 is set at apredetermined position of the portable computer mounting portion 51provided to the expansion unit main body (DS) 5, this state is detectedby the power supply control key 57 and informed to the control unit 56,and a power supply control signal for designating to the power ONoperation is sent to the power supply unit (PS UNIT) 6 through the cable50.

[0284] In the power supply unit (PS UNIT) 6, the power supply controlsignal on the cable 50 is received by the power supply controlmicroprocessor (PS-CPU) 61 through the IO port (IOP) 62.

[0285] Upon reception of the power supply control signal for designatingthe ON operation of the power supply, the power supply controlmicroprocessor (PS-CPU) 61 generates a power supply voltage necessaryfor operating the expansion unit and sends the power supply voltage tothe expansion unit main body (DS) 5 through the cable 50.

[0286] With this automatic power ON control mechanism, the work load ofthe user can be decreased, thereby improving the convenience.

[0287] In addition to the above-described automatic power ON controlmechanism using a switch, a function of sequentially applying powersupply voltages to the power supply (AC) outlets PC1 to PC3, asdescribed above, may be added.

[0288] With this automatic power ON control mechanism, the work load ofthe user can be decreased, thereby improving the convenience. In thiscase, the expansion unit main body (DS) 5 does not always need anoperation designating means such as the power supply control key (KP)57, and automatic power supply control of the entire system can berealized.

[0289] An arrangement may also be used in which, when the power ONoperation is designated on the expansion unit main body (DS) 5 side, thedesignation signal is sent to the power supply unit (PS UNIT) 6 via aradio channel.

[0290] In the above embodiment, the lock mechanism has an arrangement inwhich the lock lever is controlled to be laid/raised by aelectromagnetic plunger, and the lock lever p is engaged with the lockgroove of the portable computer, thereby fixing the portable computer ata predetermined position of the expansion unit main body. However, thearrangement is not limited to this. For example, a lock mechanism withanother arrangement may also be used in which a motor is used as adriving source, and the portable computer main body is sandwiched at itsboth sides and fixed at a predetermined position of the expansion unitmain body.

[0291] In this embodiment, as a simplest arrangement, the power supplycontrol line pulled up on the power supply unit (PS UNIT) 6 side issimply shorted to the ground line by operating the key, and a powersupply control signal on the power supply control line is set at aground (“0”) level. However, for example, when a keypad having aplurality of numeric keys is used, and a key code input by operating thekeys of the keypad is input to the control unit 56, the ON/OFF operationof the power supply of the expansion unit and feed/stop of the powersupply (AC) outlets PC1 to PC3 can be individually designated. Whenthese designations are made valid by combining specific keys, a securityfunction can also be obtained. In this case, however, a circuit foroperating the control unit 56 in a sleep mode is necessary.

[0292] An example in which the feed/stop control of the AC powersupplies of the power supply outlets PC1 to PC3 in the third embodimentis applied to the first embodiment will be described below. FIG. 15 is ablock diagram schematically showing the configuration of the computersystem in application of the feed/stop control to the first embodiment.Of the constituent elements of a portable computer 4 a and a deskstation5 a, only minimum constituent elements necessary for the description areshown in FIG. 15. In this example, the driving unit (DRV) provided tothe power supply unit (PS-UNIT) is driven and controlled by the powersupply controller of the portable computer.

[0293] The expansion unit main body (deskstation) 5 a is connected to apower supply unit (PS-UNIT) 6 a through a cable 50 a having apredetermined length. The expansion unit main body (DS) 5 a receives aDC power supply voltage from the power supply unit 6 a and applies apredetermined voltage to the constituent elements of the deskstation 5 aby using a DC/DC converter, and at the same time, applies apredetermined voltage of, e.g., 16V to the portable computer 4 a.

[0294] The power supply unit (PS-UNIT) 6 a applies a power supplyvoltage to the expansion unit main body (DS) 5 a. As shown in FIG. 15,the power supply unit 6 a has an AC/DC converter 65 for converting an ACpower supply voltage into a DC power supply voltage and generates apredetermined DC voltage in accordance with a designation sent throughthe cable 50 a and applies the voltage to the expansion unit main body(DS) 5 a. The power supply unit (PS-UNIT) 6 a has a plurality of (three)power supply (AC) outlets PC1 to PC3 which are ON/OFF-controlled withpredetermined time lags.

[0295] The cable 50 a connects the expansion unit main body (DS) 5 a andthe power supply unit (PS-UNIT) 6 a. In this case, the cable 50 a isconstituted by a power supply line for applying a DC voltage generatedby the power supply unit (PS) 6 a to the expansion unit main body (DS) 5a, and a single control signal line for supplying a control signal fordesignating the ON/OFF operation of the power supply voltage from theportable computer 4 a to the power supply unit (PS-UNIT) 6 a through theexpansion unit main body (DS) 5 a.

[0296] Referring to FIG. 15, a power supply control microprocessor(PS-CPU) 401 of the portable computer 4 a controls a power supply (PS)402 for applying a predetermined voltage to the various constituentelements of the portable computer 4 a and also enables/disables theoutlets PC1 to PC3 of the power supply unit (PS-UNIT) 6 a. Morespecifically, the power supply control microprocessor (PS-CPU) 401receives a designation of the ON/OFF operation of the power supply froma power switch (SW4) for designating the ON/OFF operation of the powersupply of the portable computer 4 a and the expansion unit main body(DS) 5 a through an IO port (IOP) 403. When a power ON operation isperformed, the AC/DC converter 65 of the power supply unit (PS-UNIT) 6a, the DC/DC converter of the deskstation main body 5 a, and the powersupply (PS) 402 are started to apply an operating voltage to eachconstituent element of the computer system. In this embodiment, thepower supply control microprocessor (PS-CPU) 401 always receives anoperating power supply voltage while an AC plug is inserted, andreceives a control signal for designating the ON/OFF operation of thepower supply as an interrupt signal. In accordance with thisinterruption, power supply control processing is performed. Morespecifically, in accordance with the control signal supplied through theIO port (IOP) 403, the power supply control microprocessor (PS-CPU) 401executes power OFF processing if the system is in a power ON state orpower ON processing if the system is in a power OFF state.

[0297] The IO port (IOP) 403 transmits the control signal between thepower supply control microprocessor (PS-CPU) 401 and the power switch(SW4). More specifically, the IO port (IOP) 403 receives a controlsignal for designating the ON/OFF operation of the power supply from thepower switch (SW4) and informs the contents of the signal to themicroprocessor (PS-CPU) 401. In this embodiment, to simplify thearrangement, one end of the power switch (SW4) is always pulled up.Every time a ground level (“0”) is set for a predetermined period oftime (e.g., 0.5 sec) in accordance with the switching operation, acontrol signal for designating the ON/OFF operation of the power supplyis supplied to the power supply control microprocessor (PS-CPU) 401.Upon reception of the power supply control signal, the power supplycontrol microprocessor (PS-CPU) 401 executes power OFF processing if thesystem is in a power ON state or power ON processing if the system is ina power OFF state.

[0298] The power supply (PS) 402 generates various voltages (+5V, +12V,and +3.3V) under the control of the power supply control microprocessor(PS-CPU) 401 and applies the voltages to the various constituentelements of the portable computer 4 a.

[0299] A deskstation interface 404 performs data transmission betweenthe power supply control microprocessor (PS-CPU) 401 and a driver 66 ofthe power supply unit (PS-UNIT) 6 a. More specifically, a designationoutput from the power supply control microprocessor (PS-CPU) 401 uponexecution of power ON processing is sent to the driver 66 through thedeskstation 5 a and the cable 50 a. A signal output from the powersupply control microprocessor (PS-CPU) 401 is sent to the deskstation 5a through a dedicated signal line and further sent to the driver 66through the cable 50 a. As the dedicated signal line from the portablecomputer 4 a to the deskstation 5 a, the predetermined pins of thecommunication connectors 13 and 26 shown in the first and secondembodiments may also be used.

[0300] Like the above-described driver 64, the driver (DRV) 66 providedto the power supply unit 6 a has a sequence controller forON/OFF-controlling the power supply (AC) outlets PC1 to PC3 andON/OFF-controls the feed switches S1 to S3 at different timings (T1 toT3) with predetermined time lags under the control of the power supplycontrol microprocessor (PS-CPU) 401.

[0301] An example of feed control of AC power supply voltages to thepower supply (AC) outlets PC1 to PC3 will be described below withreference to the flow chart in FIG. 16. The routine shown in FIG. 16 isexecuted in accordance with a predetermined timer interrupt.

[0302] The power supply control microprocessor 401 determines whetherthe power switch (SW4) is operated to power on the portable computer 4 a(step E1). Particularly, when the power switch (SW4) is not operated topower on the portable computer 4 a (NO in step E1), it is determinedwhether a power switch ON request is sent from the deskstation 5 a (stepE3). If no power switch ON request is sent, processing for determiningexecution of the power OFF processing of the portable computer 4 a isperformed. The power switch ON request is a command issued in accordancewith the operation of the power switch provided to the deskstation 5 aand sent through the communication connectors shown in the first andsecond embodiments.

[0303] When the power switch (SW4) is operated to power on the portablecomputer 4 a (YES in step E1), or when the power switch ON request isset in the deskstation interface 404, (YES in step E3), the power supplycontrol microprocessor 401 controls the power supply 402 to performpower ON processing of the portable computer 4 a (step E5). With thisoperation, operating voltages are applied to the constituent elements ofthe portable computer 4 a. Thereafter, the power supply controlmicroprocessor 401 sends a predetermined control signal to the driver 66through the deskstation interface 404, the deskstation 5 a, and thecable 50 a.

[0304] More specifically, the power supply control microprocessor 401controls the driver 66 to turn on the switch S1 (step E7). With thisoperation, the outlet PC1 is enabled. After the switch S1 is turned on,the power supply control microprocessor 401 waits for 10 ms and furthercontrols the driver 66 to turn on the switch S2 (steps E9 and E11).Thereafter, the power supply control microprocessor 401 waits for 10 msagain and then controls the driver 66 to turn on the switch S3 (stepsE13 and E15).

[0305] With this processing, the switches S1 to 53 are sequentiallyturned on, and the outlets PC1 to PC3 are sequentially enabledaccordingly.

[0306] With the above-described sequence control of the power supply(AC) outlets PC1 to PC3, a power ON/OFF sequence mechanism according tothe system configuration can be easily realized. Disadvantages such asvariations in voltage or breaker down caused by rapid power consumptiondue to rush can be prevented, thereby ensuring a stable operation.Additionally, the rated power of each equipment or line member can besuppressed to simplify the system.

[0307] In addition, when the power supply control microprocessor 401 iscontrolled in accordance with a flow chart shown in FIG. 17, the powersupply outlet control can be applied to hot/cold insertion of the powersupply controller 123 of the first embodiment. More specifically, thepower supply control microprocessor 401 receives a dock power ON commandsent from the CPU for controlling the entire portable computer 4 a (stepF1). The power supply control microprocessor 401 controls the driver 66to turn on the switch S1 in accordance with this command (step F3).Thereafter, the power supply control microprocessor 401 sequentiallyturns on the switches S2 and S3 in a wait time of 10 ms (steps F5 toF11). After ON-control of the switches S1 to S3 is completed, and allthe power supply outlets PC1 to PC3 are enabled, a dock start command isoutput to the deskstation 5 a (step F13). With this operation, even whenthe power supply unit (PS-UNIT) 6 a is provided to the computer systemof the first embodiment, sequence control of the power supply outlets asin the third embodiment can be performed. When this control is to beapplied to the second embodiment, sequence control may be performed inaccordance with a dock completion command on the deskstation side.

[0308] Such sequence control can be performed by the power supply unit(PS-UNIT) 6 a by providing a control processor to the power supply unit6, as shown in FIG. 12.

[0309] An example in which the above-described lock mechanism control ofthe third embodiment is applied to the loading/ejecting operation of thefirst embodiment will be described below.

[0310] The control unit 56 of the deskstation main body 5 in FIG. 13 isconstituted by a microprocessor for controlling the expansion unit mainbody (DS) 5. In this case, a power switch ON command for designating theON/OFF operation of the power supply, which is input by operating thecontrol key 57, is sent to the deskstation interface 404 shown in FIG.15, and at the same time, the power supply (PS) 59 is controlled toapply three DC power supply voltages (PV) to internal circuits. In thisembodiment, when the control key 57 is operated, a power supply controlline which is pulled up in advance is shorted to the ground line tooutput a power switch ON command for designating the ON/OFF operation ofthe power supply. A designation for turning on the switches S1 to S3 maybe sent to the driver 66 in accordance with this control key.

[0311] The status detection switch 58 detects that the portable computer(PC) 4 is set at a predetermined position of the portable computermounting portion 51 and informs the detection state to the control unit56. The status detection switch 58 corresponds to the switch S1 shown inthe first and second embodiments.

[0312] For the descriptive convenience, it is assumed that the portablecomputer 4 has the same constituent elements as those of the portablecomputer 4 a shown in FIG. 15. It is also assumed that the portablecomputer (PC) 4 has a control unit for controlling the entire portablecomputer (PC) 4.

[0313] An example in which control using the lock mechanism 54 isapplied to the first embodiment will be described below with referenceto FIGS. 18 and 19. In control shown in FIGS. 18 and 19, lock processingis performed at the time of docking in accordance with a password whichis designated in advance, and unlock processing is performed at the timeof undocking. The password may be input from a ten-key pad connectableto the deskstation 5, set using the control key 57, or set from akeyboard provided to the main body of the portable computer 4. Thepassword is held in a predetermined nonvolatile memory in the portablecomputer 4. A flag (password flag) representing setting of the passwordis provided in the power supply control microprocessor 401. This-lockprocessing can also be applied to the second embodiment.

[0314] First of all, loading processing will be described with referenceto FIG. 18. In accordance with a dock request command sent from thedeskstation 5 when the portable computer 4 is in a power OFF state, orin accordance with a dock power ON command from the control unit forcontrolling the entire portable computer 4 when the portable computer 4is in a power ON state, the power supply control microprocessor 401determines whether the password flag is set (step G1). If the passwordis set, a dock and lock start command is issued to the deskstation 5(step G3). The control unit (CNT) 56 of the deskstation 5 executesloading processing in accordance with the dock and lock start commandand drives the driving unit (DRV) 55 to, operate the lock mechanism 54,thereby stationarily holding the portable computer (PC) 4 at apredetermined position of the mounting portion 51 (step G5).

[0315] If the password flag is not set (NO in step G1), a dock startcommand is issued, as in the first embodiment (step G5). The controlunit 56 of the deskstation 5 executes only loading processing inaccordance with the dock start command (step G7).

[0316] With the above processing, the above-described lock control canbe applied to connect the portable computer 4 to the deskstation 5.

[0317] If the password is set while the portable computer 4 connected tothe deskstation 5 without setting a password is being used, the drivingunit (DRV) 55 may be driven in accordance with this setting to operatethe lock mechanism 54, thereby stationarily holding the portablecomputer (PC) 4 at a predetermined position of the mounting portion 51.

[0318] An operation of detaching the portable computer 4 from thedeskstation 5 will be described below with reference to FIG. 19.

[0319] The control unit 56 of the deskstation 5 issues an eject requestcommand in accordance with the operation of the power switch provided tothe deskstation 5 or the control key (step H1). The power supply controlmicroprocessor 401 determines in accordance with the eject requestcommand whether the password is set from the presence/absence of thepassword flag (step H3). If the password flag is not set (NO in stepH3), an eject start command is issued (step H5). The control unit 56 ofthe deskstation 5 executes eject processing in response to the ejectstart command (step H7).

[0320] If the password flag is set (YES in step H3), the power supplycontrol microprocessor 401 performs power ON processing (step H9). Withthis processing, the portable computer 4 is forcibly powered on.

[0321] Upon the forced power ON operation, the control unit of theportable computer 4 requests a password from the operator and checkswhether the password is correct (step H11). If the received password isnot correct (NG in step H11), the control unit of the portable computer4 ends the processing. Thereafter, the control unit of the portablecomputer 4 may send a command for requesting the power OFF operation ofthe portable computer 4 to the power supply control microprocessor 401such that the portable computer 4 is set in a power OFF state again.

[0322] If the received password is correct (OK in step H11),configuration set processing is performed as in the first embodiment(step H13). The control unit of the portable computer 4 performspredetermined processing and issues an eject permission command (stepH15). The power supply control microprocessor 401 issues an unlock andeject start command in accordance with the eject permission command(step H17). The control unit 56 of the deskstation 5 executes unlockprocessing in accordance with the unlock and eject start command andthereafter performs eject processing (steps H19 and H17).

[0323] With the above processing, unlock control in detachment of theportable computer 4 from the deskstation 5 is performed. Independentlyof execution of the eject processing, a specific command may be input tooperate the lock mechanism 54 for unlocking., However, it is necessarythat the specific command input at this time is known by a few personssuch as the manager of the computer system.

[0324] The processing in the flow chart of FIG. 19 shows an operation ofdetaching the portable computer 4 in a power OFF state, i.e., a coldejecting operation. In a hot ejecting operation, processing for checkingthe password need to be performed in an SMI routine started by an SMI.

[0325] The above-described password may be held in a predeterminednonvolatile memory on the deskstation 5 side.

[0326] Registration/deletion management of the password used for controlof the lock mechanism 54 will be described below with reference to FIGS.45 and 46. It is assumed that password management is performed by thecontrol unit 56 for controlling the entire deskstation 5. A password(PW) can be registered/deleted using the control key 57. FIG. 45 is aview showing an example of the control key 57. As shown in FIG. 45, thecontrol key 57 has numeric keys “0” to “9”, “.” and “#” keys, a CLR(clear) key, an end key, and a return key. The control key 57 can beattached/detached to/from the deskstation 5. The password (PW) is heldin an EEPROM provided in the deskstation 5. In addition to the password,a PW suspend flag representing whether the password is held, a PW checkinterruption flag representing that interrupt processing is performedduring check of the password, and the like are held in the EEPROM.

[0327] The control unit 56 executes the following processing in the flowchart of FIG. 46 in accordance with a timer interrupt everypredetermined period of time. The control unit 56 determines whether thePW suspend flag is set in the EEPROM (step K1). If the suspend flag isnot set (NO in step K1), key scan is performed to determine whether anykey is depressed. If YES, it is determined whether the depressed key isthe end key (steps K3 and K5). If any key of the control key 57 is notdepressed (NO in step K3), password control processing is ended.

[0328] If the depressed key is not the end key (NO in step K5), it isdetermined whether the depressed key is the clear key (step K7). If thedepressed key is the clear key (YES in step K7), a pointer is cleared.This pointer indicates a position in the register for holding aplurality of characters of a key code corresponding to character(numeric) keys input using the control key 57. If the depressed key isnot the clear key (NO in step K7), a key code corresponding to thedepressed key is stored in an area indicated by the pointer, and thepointer is incremented by one (steps K11 and K13).

[0329] When the PW suspend flag is not set in step K1, or when it isdetermined in step K5 that the end key is depressed, it is determined inthe computer system including the deskstation 5 whether loading or ejectprocessing is being executed (step K15). If some processing is beingexecuted (YES in step K15), the PW check interrupt flag is set to apredetermined memory area (step K17), thereby ending the passwordcontrol processing. If the processing which is being executed in stepK17 is ended, the control unit 56 refers to the PW check interruptionflag to determine whether password control processing is beingperformed. If the PW check interruption flag is set, processing in FIG.46 is resumed.

[0330] In step K15, if neither loading nor eject processing is beingexecuted, the PW suspend flag is cleared, and it is determined whetherthe first two of the received characters are “##” (steps K19 and K21).If the first two characters are not “##” (NO in step K21), the controlunit 56 compares the characters which are input using the control key 57with the password held in the EEPROM (step K23). If the input characterscoincide with the held password (OK in step K23), the lock mechanism 54is controlled to perform unlock processing (step K25). If the receivedcharacters do not coincide with the password (NG in step K23), the PWsuspend flag is set again, thereby ending password processing.

[0331] If the first two of the received characters are “##” in step K21,the control unit 56 determines whether registration (deletion) of thepassword is to be performed (step K27). More specifically, when thefirst two of the received characters are “##”, it is recognized that thecharacters input by the operator designate to register or delete thepassword, and it is determined whether the password is already input. Ifthe password is not registered yet, characters subsequent to the thirdcharacter are input as a password. Thereafter, the pointer is cleared(steps K29 and K31).

[0332] If the password is already registered (YES in step K27), thepassword held in the EEPROM is compared with the received characters(step K33). If the registered password coincides with the inputcharacters (OK in step K35), the PW suspend flag is cleared, andregistration of the password is canceled. If the password registered inthe EEPROM does not coincide with the received characters (NG in stepK33), input by the operator is ignored, thereby ending the processing.

[0333] With the above processing, password registration/deletion fordriving the lock mechanism can be performed from the deskstation 5.Therefore, while the lock mechanism is being driven after registrationof the password, the portable computer 4 is prevented from beingdetached from the deskstation 5 by a third party.

[0334] A modification of the third embodiment will be described belowwith reference to FIGS. 20 and 21. FIG. 20 is a side view showing astate in which a portable computer 4A, a port replicator 7A, andexpansion units 5A and 5B are connected to each other. FIG. 21 is aperspective view of the portable computer 4A, and the port replicator 7Aconnected to the expansion units 5A and 5B.

[0335] A connector group 405 including an RGB connector and a printerconnector, and an expansion connector 406 connected to a system bus inthe portable computer 4A are provided on the rear surface of theportable computer 4A. The port replicator 7A has a connector connectableto the connector group 405 and the expansion connector 406 of theportable computer 4A and is connected to the rear surface of theportable computer 4A. The port replicator 7A has a connector group 71including an RGB connector and a printer connector on a surface oppositeto that connected to the portable computer 4A. The connector group 71 isconnected to the connector group 405 through the port replicator 7A.Therefore, the portable computer 4A can be connected to a CRT monitor, aprinter, and the like through the port replicator 7A. With the portreplicator 7A, the operator need not sequentially detach the terminalsof external equipments connected to the rear surface before the portablecomputer 4A is carried. The operator only need to detach the portreplicator 7A. To the contrary, when external equipments such as a CRTmonitor and a printer are to be connected to the portable computer 4A,these external equipments can be used only by connecting the portablecomputer 4A to the port replicator 7A as far as desired externalequipments are connected to the connector group 71 of the portreplicator 7A in advance.

[0336] The port replicator 7A has an expansion connector 72 on the lowersurface portion. The expansion connector 72 is connected inside the portreplicator 7A to a connector which is connected in correspondence withthe expansion connector 406 of the portable computer 4A. Therefore, whenthe portable computer 4A is connected to the port replicator 7A, theexpansion connector connected to the bus of the portable computer 4Aappears to the lower surface portion of the port replicator 7A.

[0337] The expansion units 5A and 5B are detachable. In FIG. 20, theexpansion unit 5A is connected to the lower surface portions of theportable computer 4A and the port replicator 7A while the expansion unit5B is connected to the lower surface portion of the expansion unit 5A.Each of the upper and lower surfaces of the expansion units 5A and 5Bhas the same area as that of the lower surface of the portable computer4A and the port replicator 7A in a connected state. When the expansionunits 5A and 5B are arranged as a single housing under the portablecomputer 4A and the port replicator 7A in a connected state, theexpansion units 5A and 5B respectively have connectors 502A and 502Bwhich oppose the expansion connector 72 of the port replicator 7A. Theconnectors 502A and 502B are connected to expansion connectors 503A and503B in the lower surface portions through buses 501A and 501B in theexpansion units 5A and 5B. Therefore, when the expansion unit 5A isarranged under the portable computer 4A and the port replicator 7A in aconnected state, the expansion connector 72 of the port replicator 7Acan be connected to the connector 502A provided on the upper surface ofthe expansion unit 5A. The expansion unit 5B also has the samestructure.

[0338] In addition, one of the expansion units 5A and 5B can beconnected to the upper surface of the other. As shown in FIG. 20, whenthe expansion unit 5B is arranged under the expansion unit 5A, theexpansion connector 503A of the expansion unit 5A can be connected tothe connector 502B of the expansion unit 5B.

[0339] With this arrangement, the portable computer 4A, the portreplicator 7A, and the expansion units 5A and 5B can be connected toeach other, as shown in FIG. 20. In this case, the system bus of theportable computer 4A is connected to an external equipment mounted inthe expansion unit 5A through the expansion connector 406, the expansionconnector 72 of the port replicator 7A, and the connector 502A and thebus 501A of the expansion unit 5A, and to an external equipment mountedin the expansion unit 5B through the expansion connector 503A, and theconnector 502B of the expansion unit 5B. As shown in FIG. 20, a CD-ROMdrive and a hard disk drive (HDD) are mounted in the expansion units 5Aand 5B, respectively.

[0340] An additional expansion unit can be connected to this computersystem. More specifically, as shown in FIG. 20, an expansion unit 5Chaving a communication card (ISA card) corresponding to an ISA bus canalso be connected.

[0341] The computer system having the above configuration caneffectively use the port replicator and easily connect an expansion unithaving an expansion equipment. Therefore, the function can be easilyexpanded.

[0342] The fourth embodiment of the present invention will be describedbelow with reference to the accompanying drawings.

[0343]FIG. 22 is a block diagram showing a system configurationaccording to the fourth embodiment of the present invention.

[0344] Referring to FIG. 22, a CPU (CPU device) 610 has a cache memoryas one chip constituted by a semiconductor integrated circuit. The CPU610 is constituted by bipolar CMOSs and has a control terminal (Pa) forreceiving a clock stop control signal (STP-CLK) for stopping the clockto stop execution of a command, and a forced interrupt terminal (Pb) forreceiving a forced interrupt (system management interrupt called an SMIis exemplified in this embodiment).

[0345] In the fourth embodiment, as control for decreasing the chiptemperature of the CPU 610, CPU temperature control is exemplified inwhich the clock stop control signal (STP-CLK) supplied to the controlterminal (Pa) is not used for the original clock stop control but forswitching control for lowering the clock frequency supplied to the CPU610 to decrease the speed, thereby decreasing the chip temperature.

[0346] In the chip of the CPU 610, a p-n junction circuit element 611constituting, e.g., a silicon diode for measuring the temperature in thechip is arranged on an internal integrated circuit substrateconstituting the CPU. Pins (Pc and Pd) dedicated to the p-n junctioncircuit element are assigned to the connection terminal portion of thechip.

[0347] As is known, a silicon diode constituted by the p-n junctioncircuit element 611 has temperature drift characteristics of about −2 to−2.5 mV/C. Therefore, when a forward current path is formed between ananode and a cathode, the voltage on the anode side changes depending onthe peripheral temperature, and the voltage becomes lower with anincrease in temperature. As indicated by a broken line in FIG. 22, aforward current path is formed between the pins (Pc and Pd) dedicated tothe p-n junction circuit element 611, and a signal with a change involtage, which is obtained from the dedicated pins (Pc and Pd), isexternally output as a temperature detection signal (TH).

[0348] The CPU 610 also has a PLL (phase locked loop) circuit 612 forgenerating an internal operating clock on the basis of a reference clock(B-CLK) input from the outside, an internal clock controller (G) 613 forcontrolling supply of the clock generated by the PLL (phase locked loop)circuit 612 to an internal circuit, and the like.

[0349] A system power supply control unit (PSC) 620 uses amicroprocessor to realize an intelligent power supply. The system powersupply control unit (PSC) 620 has an A/D (analog-to-digital) converter621 and a power supply control microprocessor (μp) 622. The power supplycontrol microprocessor (μp) 622 receives signal states from variousobservation targets through the A/D (analog-to-digital) converter 621and recognizes the states, thereby controlling various power suppliesand operations including the ON/OFF control of the operating powersupply. In this embodiment, the temperature detection signal (TH)obtained from the pins (Pc and Pd) dedicated to the p-n junction circuitelement 611 provided in the CPU 610 is supplied to the A/D(analog-to-digital) converter 621, and the analog temperature detectionsignal (TH) with a change in voltage is converted into a digital signal.The digital temperature detection signal (TH) is recognized by the powersupply control microprocessor (A p) 622 and compared with apredetermined set voltage value. When the value of the temperaturedetection signal (TH) exceeds the set voltage value, a CPU temperaturecontrol command for informing the state is set in a status register in astatus LCD control gate array (SLCDC-GA) 630, and an SMI issue commandis set in an SMI register in the gate array 630.

[0350] The gate array (SLCDC-GA) 630 is a peripheral control gate arrayhaving a register group including a status register and an SMI register.In this embodiment, the status LCD control gate array (SLCDC-GA) forperforming display control of a status LCD (not shown) as a mainfunction is exemplified. In this embodiment, an interrupt generationfunction using the status and SMI registers of the gate array is used.In accordance with various CPU temperature control commands issued whenthe temperature detection signal (TH) exceeds the set voltage value,predetermined status and SMI registers are set, and a system managementinterrupt (SMI) is issued from the system power supply control unit(PSC) 620.

[0351] A system control gate array (SYS·CONT-GA) 640 is a gate arrayincorporating various logic circuits for system control. The systemcontrol gate array (SYS·CONT-GA) 640 generates the system managementinterrupt (SMI) to the CPU 610 on the basis of the system managementinterrupt (SMI) as one factor for CPU temperature control, which isreceived from the status LCD control gate array (SLCDC-GA) 630; andoutputs a clock switching signal (CLK-C), the clock stop control signal(STP-CLK), and the like under the control of the CPU 610.

[0352] A clock controller (CLK-CONT) 650 generates and outputs thereference clock (B-CLK) as a reference of the operating clock of the CPU610. In this embodiment, the clock controller (CLK-CONT) 650 receivesthe clock switching control signal (CLK-C) output from the systemcontrol gate array (SYS·CONT-GA) 640, thereby switching the clockfrequency. In this case, upon reception of the clock switching controlsignal (CLK-C), the clock supplied to the CPU 610 is retarded at apredetermined rate.

[0353]FIG. 23A is a sectional view showing the structure of the p-njunction circuit element 611 constituting, e.g., a silicon diode formeasuring the temperature in the chip, which is arranged on theintegrated circuit substrate in the CPU 610. Referring to FIG. 23A,P-Sub denotes a p-type semiconductor integrated circuit substrate;CPU-area, a circuit mounting area of the CPU 611 having a cache memory;and N-well, an n-type well.

[0354]FIGS. 24 and 25 are charts showing relationships betweentemperatures and processing in the above embodiment.

[0355] Tsd, Trst, and Tpof represent set temperatures for chiptemperature control of the CPU 610. These set temperatures are comparedwith the temperature detection signal (TH) representing the chiptemperature in the CPU 610 by the power supply control microprocessor(fp) 622 of the system power supply control unit (PSC) 620 and set tosatisfy a relationship [Tsd<Trst<Tpof].

[0356] More specifically, Tsd is a set temperature for decreasing thespeed of the CPU 610. When a chip temperature (CPU-TH) of the CPU 610amounts to the set temperature Tsd, the system management interrupt(SMI) is issued from the power supply control microprocessor (μp) 622through the system control gate array (SYS. CONT-GA) 640 to decrease thespeed (clock speed) of the CPU 610, thereby decreasing the heat amountof the CPU 610.

[0357] Trst is a set temperature for canceling (resetting) thespeed-down control of the CPU 610. When the chip temperature (CPU-TH) ofthe CPU 610 falls to the set temperature Trst, the above speed-downoperation is canceled, thereby restoring a normal processing speedaccording to setup or another setting means.

[0358] Tpof is a set temperature for performing a forced power OFFoperation of the apparatus (system main body). When the chip temperature(CPU-TH) of the CPU 610 further increases regardless of the speed-downcontrol according to the set temperature Tsd because of a severeapplication condition including peripheral environment, and amounts tothe set temperature Tpof, the system management interrupt (SMI) isissued to execute auto resume processing (power OFF processing isperformed after suspend processing).

[0359] As for a detailed means for recognizing the chip temperature(CPU-TH) by the power supply control microprocessor (μp) 622, forexample, a voltage input through the A/D (analog-to-digital) converter621 is integrated during a time t, and an average value is defined as avoltage at a certain point of time.

V1=Σ(ΔV1)/t  (1)

[0360] A chip temperature T1 is obtained from a voltage V1, a known CPUreference temperature T0, a voltage V0, and a temperature driftcoefficient A.

T1=(V1−V0)/A+T0  (2)

[0361] The temperature T1 obtained by equation (2) is defined as thechip temperature (CPU-TH) of the CPU 610 and compared with the settemperatures Tsd, Trst, and Tpof.

[0362]FIG. 24 is a chart showing processing according to the settemperatures Tsd and Trst. P1 represents a timing when the systemmanagement interrupt (SMI) is issued to decrease the speed of the CPU610. P2 represents a timing when the system management interrupt (SMI)is issued to restore the original speed of the CPU 610.

[0363]FIG. 25 is a chart showing processing according to the settemperature Tpof. Pa represents a timing when the system managementinterrupt (SMI) is issued to execute auto resume processing (power OFFprocessing is performed after suspend processing).

[0364]FIG. 26 is a flow chart showing the CPU temperature controlprocessing routine executed by the power supply control microprocessor(μp) 622 of the system power supply control unit (PSC) in thisembodiment.

[0365]FIG. 27 is a flow chart showing the SMI processing routine of CPUtemperature control executed by the CPU 610 in this embodiment.

[0366]FIGS. 30A and 30B are timing charts for explaining a clockretardation control operation by CPU temperature control in thisembodiment.

[0367] An operation according to the fourth embodiment of the presentinvention will be described below with reference to the above drawings.In the fourth embodiment, as control for decreasing the chip temperatureof the CPU 610, CPU temperature control is exemplified in which the stopcontrol signal (STP-CLK) supplied to the control terminal (Pa) is notused for the original clock stop control (FIGS. 31A and 31B) but forswitching control for lowering the clock frequency supplied to the CPU610 to decrease the speed, as shown in FIGS. 30A and 30B, therebydecreasing the chip temperature.

[0368] As shown in FIGS. 22 and 23A, a forward current path is formedbetween the dedicated pins (Pc and Pd) for externally guiding the twoterminals (the anode and the cathode) of the p-n junction circuitelement 611 arranged on the integrated circuit substrate of the CPU 610.The voltage between the pins (Pc and Pd) is changed by a temperaturedrift of the p-n junction circuit element 611, which is caused due to anincrease in chip temperature.

[0369] More specifically, the p-n junction circuit element 611 directlyreceives heat generated in the chip and changes the detection voltage ofthe dedicated pins (Pc and Pd) with temperature drift characteristics ofabout −2 to −2.5 mV/° C. as the chip temperature increases. A signalwith a change in voltage, which is obtained from the dedicated pins (Pcand Pd), is externally output from the CPU chip as the temperaturedetection signal (TH).

[0370] The temperature detection signal (TH) obtained from the dedicatedpins (Pc and Pd) of the CPU chip is supplied to the A/D(analog-to-digital) converter 621 of the system power supply controlunit (PSC) 620. The analog temperature detection signal (TH) with achange in voltage is converted into a digital signal.

[0371] The digital temperature detection signal (TH) is recognized bythe power supply control microprocessor (μp) 622 and compared with apredetermined set voltage value. When the value of the temperaturedetection signal (TH) exceeds the set voltage value, a CPU temperaturecontrol command for informing this state is set in the status registerin the status LCD control gate array (SLCDC-GA) 630.

[0372] More specifically, the power supply control microprocessor (μp)622 of the system power supply control unit (PSC) 620 refers to a clockretardation control flag (F) provided in an internal register in the CPUtemperature check routine (step I1 in FIG. 26). If the flag is set in anOFF state, the chip temperature (CPU-TH) according to the temperaturedetection signal (TH) is compared with the set temperature Tsd, therebydetermining whether the chip temperature (CPU-TH) amounts to the settemperature Tsd (step I3).

[0373] Upon recognizing that the chip temperature (CPU-TH) according tothe temperature detection signal (TH) amounts to the set temperature Tsd(timing P1 in FIG. 24), the power supply control microprocessor (μp) 622sets the clock retardation control flag (F) in the internal register toan ON state (step 15 in FIG. 26), issues a CPU temperature controlcommand for designating clock retardation control, and sets the commandin the status register in the status LCD control gate array (SLCDC-GA)630. At the same time, the power supply control microprocessor (μp) 622sets the SMI register and issues the system management interrupt (SMI)from the system control gate array (SYS·CONT-GA) 640 through the SMIregister (steps I7 and I9).

[0374] The system management interrupt (SMI) is input to the forcedinterrupt terminal (Pb) of the CPU 610.

[0375] Upon reception of the system management interrupt (SMI) by theforced interrupt terminal (Pb), the CPU 610 fetches the contents of theregister of the status LCD control gate array (SLCDC-GA) 630 through asystem bus (SYS-BUS) (step J1 in FIG. 27). If the contents of theregister represent a CPU temperature control command for designatingclock retardation control (YES in step J3), the clock stop controlsignal (STP-CLK) is output from the system control gate array(SYS·CONT-GA). 640 through the system bus (SYS-BUS), and thereafter, theclock switching control signal (CLK-C) is output (step J5).

[0376] The clock stop control signal. (STP-CLK) is supplied to thecontrol terminal (Pa) of the CPU 610 while the clock switching controlsignal (CLK-C) is supplied to the clock controller (CLK-CONT) 650.

[0377] Upon reception of the clock stop control signal (STP-CLK), theCPU 610 ends processing at a current clock period in a predeterminedunit of processing and prepares for processing at a new clock speed.Upon reception of the clock switching control signal (CLK-C), the clockcontroller (CLK-CONT) 650 retards the clock supplied to the CPU 610 at apredetermined rate.

[0378] With this processing, the clock speed of the CPU 610 is retarded,and accordingly, the heat amount is reduced to decrease the chiptemperature in the CPU 610.

[0379] When the clock retardation control flag (F) is referred to (stepI1 in FIG. 26), and the flag (F) is in an ON state, the temperaturedetection signal (TH) is compared with the set temperature Tpof, therebydetermining whether the chip temperature (CPU-TH) in the CPU 610 amountsto the set temperature Tpof (step 111 in FIG. 26).

[0380] Upon recognizing that the chip temperature (CPU-TH) in the CPU610 amounts to the set temperature Tpof, an auto resume start command isissued and set in the status register in the status LCD control gatearray (SLCDC-GA) 630, and the system management interrupt (SMI) isissued from the system control gate array (SYS·CONT-GA) 640 through theregister (steps 121 and 123 in FIG. 26).

[0381] Upon reception of the system management interrupt (SMI), the CPU610 fetches the contents of the register of the status LCD control gatearray (SLCDC-GA) 630 through the system bus (SYS-BUS) (step J1 in FIG.27). If the contents of the register represent an auto resume startcommand (YES in step J11), suspend processing is executed (step J13),and auto power OFF processing is executed (step J15).

[0382] If the clock retardation control flag (F) is in an OFF state (YESin step 11 in FIG. 26), and the chip temperature (CPU-TH) of the CPU 610does not amount to the set temperature Tpof (NO in step 111), thetemperature detection signal (TH) is compared with the set temperatureTrst, thereby determining whether the chip temperature (CPU-TH) of theCPU 610 falls to the set temperature Trst (step I13).

[0383] Upon recognizing that the chip temperature (CPU-TH) of the CPU610 falls to the set temperature Trst, the clock retardation controlflag (F) is set in an OFF state (step 115), a clock retardation cancelcommand is issued and set in the status register in the status LCDcontrol gate array (SLCDC-GA) 630, and the system management interrupt(SMI) is issued from the system control gate array (SYS·CONT-GA) 640through the

[0384] register (steps I17 and I19).

[0385] Upon reception of the system management interrupt (SMI), the CPU610 fetches the contents of the register of the status LCD control gatearray (SLCDC-GA) 630 through the system bus (SYS-BUS) (step J1 in FIG.27). If the contents of the register represent a CPU temperature controlcommand for clock retardation cancel (YES in step J7), a clockretardation cancel command is issued to cancel the clock switchingcontrol signal (CLK-C) output from the system control gate array (SYS.CONT-GA) 640 through the system bus (SYS-BUS) (step J9).

[0386] When the clock switching control signal (CLK-C) is canceled, theclock controller (CLK-CONT) 650 restores the speed of the clock suppliedto the CPU 610 to the original speed according to setup or anothersetting means, thereby restoring the operation of the CPU 610 to thenormal processing speed.

[0387] In the above embodiment, as control for decreasing the chiptemperature of the CPU 610, the clock frequency supplied to the CPU 610is lowered to decrease the speed, thereby decreasing the chiptemperature. Instead, as shown in FIGS. 31A and 31B, temperaturedecrease control can also be used in which an internal clock (CPU-CLK)is intermittently stopped for a predetermined period of time inaccordance with the stop control signal (STP-CLK) supplied to thecontrol terminal (Pa) of the CPU 610 when a CPU temperature control SMIis issued.

[0388] More specifically, upon recognizing that the chip temperature.(CPU-TH) of the CPU 610 amounts to the set temperature Tsd (timing P1 inFIG. 24), the power supply control microprocessor (fp) 622 sets theclock retardation control flag (F) provided in the internal register toan ON state, issues a clock stop command and sets it in the statusregister in the status LCD control gate array (SLCDC-GA) 630, and issuesthe system management interrupt (SMI) from the system control gate array(SYS. CONT-GA) 640 through the register.

[0389] Upon reception of the system management interrupt (SMI), the CPU610 fetches the contents of the register of the status LCD control gatearray (SLCDC-GA) 630 through the system bus (SYS-BUS). If the contentsof the register represent a clock stop command, the clock stop controlsignal (STP-CLK) is output from the system control gate array(SYS·CONT-GA) 640 through the system bus (SYS-BUS).

[0390] The clock stop control signal (STP-CLK) is supplied to thecontrol terminal (Pa) of the CPU 610.

[0391] Upon reception of the clock stop control signal (STP-CLK) at thecontrol terminal (Pa), the CPU 610 intermittently stops the internalclock to execute processing while setting an OFF time having apredetermined period. By setting an OFF time having a predeterminedperiod, temperature decrease control is performed to fall the chiptemperature of the CPU 610.

[0392] Upon recognizing that the chip temperature (CPU-TH) of the CPU610 falls to the set temperature Trst, clock stop control is canceled torestore the normal operation.

[0393] With this chip temperature control, the change in chiptemperature of the CPU 610 can be rapidly and accurately reflected tocontrol of the internal circuit of the CPU 610, thereby suppressing anincrease in chip temperature of the CPU 610.

[0394] Instead of the above temperature control for lowering the clockfrequency, or temperature control for intermittently stopping theinternal clock while setting an OFF time having a predetermined period,temperature control for executing a HALT instruction in accordance withissue of the SMI can also be performed, as shown in FIGS. 31A and 31B.More specifically, when the CPU temperature control SMI is issued, theHALT instruction is executed, and an interrupt or the like is generatedafter a predetermined period of time to perform the normal operation. Inthe HALT state, the operation of the internal circuit is stopped, sothat the heat amount of the chip temperature is decreased.

[0395] Modifications of the fourth embodiment will be described belowwith reference to FIGS. 23B, 23C, 28, and 29.

[0396]FIGS. 23B, 23C, 28, and 29 shows other embodiments of the chiptemperature detection element of the CPU 610.

[0397] In FIG. 23B, in place of the p-n junction circuit element 611 ofthe embodiment shown in FIG. 23A, a transistor circuit element isarranged, near the heat generating portion (hot spot) of the integratedcircuit substrate in the chip of the CPU 610 as an element for measuringthe internal temperature of the chip.

[0398] The temperature detector using the transistor circuit elementalso has temperature drift characteristics as in the p-n junctioncircuit element 611 of the embodiment shown in FIG. 23A. For thisreason, the temperature in the chip can be directly monitored bymonitoring a base-to-emitter voltage.

[0399] In FIG. 23C, in place of the p-n junction circuit element 611 ofthe embodiment shown in FIG. 23A, a thermistor circuit element is buriednear the heat generating portion (hot spot) of the integrated circuitsubstrate in the chip of the CPU 610 as an element for measuring theinternal temperature of the chip.

[0400] In the temperature detector using the thermistor circuit element,when a change in resistance according to a change in temperature of thethermistor circuit element is detected by a voltage, the temperature inthe chip can be directly monitored.

[0401] In FIG. 28, as an element for measuring the internal temperatureof the chip, a buffer circuit 614 is buried near the heat generatingportion (hot spot) of the integrated circuit substrate of the chip ofthe CPU 610, and a response delay caused due to a change in temperaturein the chip is used to measure the temperature in the chip. In thiscase, the reference clock (B-CLK) with a predetermined frequency isapplied to the buffer circuit 614, and an output from the buffer circuit614 is supplied to a phase comparator (PH-COM) 660. Phase comparisonwith respect to the reference clock (B-CLK) is performed, and the chiptemperature is detected from an analog signal according to the dutyratio.

[0402]FIG. 29 shows a CPU chip 602. The CPU chip 602 is constituted byintegrally forming a temperature measurement element (chip) 601 and anintegrated circuit substrate 600 of the CPU 610 with a molding resin. Inthe CPU chip 602, the temperature measurement element 602 is arranged atthe heat generating portion (hot spot) on the integrated circuitsubstrate 600, and dedicated pins (Pi and Pj) are provided, therebyperforming temperature control similar to the above embodiment.

[0403] In the embodiments shown in FIGS. 23A to 23C, 28, and 29, insteadof arranging a single temperature detection element, a plurality oftemperature detection elements-may be arranged on the integrated circuitsubstrate to detect the chip temperature. In this case, the temperaturedetection elements are separately provided at a plurality of portions onthe integrated circuit substrate. In either an arrangement in whichthese temperature detection elements are connected in series, and one ortwo dedicated pins are assigned for temperature detection or anarrangement in which one or two dedicated pins are assigned to therespective temperature detection elements which are separately arrangedat a plurality of portions on the integrated circuit substrate, thedetection precision and response characteristics can be furtherimproved.

[0404] In the above embodiment, two dedicated pins are assigned to thetemperature detection element. However, one terminal of the element maybe connected to a ground terminal (GND) or another specific pin, and onededicated pin may be assigned to the temperature detection element.

[0405] As described above in detail, according to the present invention,a one-chip controller capable of rapidly and accurately recognizing achange in temperature in the chip can be provided. In addition, thechange in temperature in the one-chip controller can be rapidly andaccurately reflected to circuit control in the one-chip controller,thereby efficiently driving and controlling the one-chip controller toalmost the operating limitation.

[0406] The fifth embodiment according to the present invention will bedescribed below. The method described in the fourth embodiment can beapplied to or combined with temperature detection and clock control inthe fifth embodiment (to be described later). Additionally, in the fifthembodiment, a fan is arranged in the deskstation to cool a heatgenerating portion such as a CPU and a CPU board.

[0407] The first example of the fifth embodiment is shown in FIGS. 33Aand 33B. A computer system shown in FIGS. 33A and 33B is constituted bya portable computer 70 and a deskstation 80 used to expand the functionof the portable computer 70. The portable computer 70 can beattached/detached to/from the deskstation 80, as shown in FIG. 33A, andthe control in the first or second embodiment can be applied forattachment/detachment.

[0408]FIG. 33B shows the structure of the computer system. As shown inFIG. 33B, the portable computer 70 has a suction port 71 in the frontsurface of the main body and an exhaust port 72 in the rear surface. Thedeskstation 80 used to expand the function of the portable computer 70has sensors (S) 81 a and 81 b, a fan 82, and a drive controller (DRV)83. The deskstation 80 also has a suction port 84 in a surface connectedto an expansion or communication connector and an exhaust port 85 forexhausting air in the rear surface. When the portable computer 70 isloaded in (connected to) the deskstation 80, the exhaust port 72 of theportable computer 70 contacts the suction port 84 of the deskstation 80to oppose each other.

[0409] The sensors 81 a and 81 b detect the temperature of a CPU chip(CPU board) incorporated in the portable computer 70 mounted in thedeskstation 80. Two sensors are provided in this embodiment. However,for the purpose of cooling the CPU chip, only one sensor may besufficiently arranged near the CPU chip. The fan 82 draws hot air in theportable computer 70 through the suction port 84 and externally exhauststhe air through the exhaust port 85 under the control of the drivecontroller 83. The drive controller 83 controls the fan 82 in accordancewith detection signals from the sensors 81 a and 81 b, therebyexchanging air in the portable computer 70, which is heated by the heatgenerating portion such as the CPU chip and the CPU board. With thisoperation, when the portable computer 70 is mounted in the deskstation80 serving as a function expansion unit, degradation in heat dissipationof the portable computer 70 can be covered, thereby maintaining areliable function expansion operation.

[0410] In this structure, the internal temperature of the portablecomputer 70 mounted in the portable computer mounting portion of thedeskstation 80 is detected by the temperature sensors (S) 81 a and 81 b,and detection signals are supplied to the drive controller (DRV) 83.

[0411] When one of detection temperatures from the temperature sensors(S) 81 a and 81 b amounts to a set temperature, the drive controller(DRV) 83 drives the air-cooling fan 82 to draw hot air in the portablecomputer 70 through the exhaust port 72 and the suction port 84 andexhaust the air through the exhaust port 85.

[0412] With this cooling mechanism of the portable computer, degradationin heat dissipation of the portable computer 70 mounted in thedeskstation 80 can be covered, thereby maintaining a reliable functionexpansion operation. The fan 82 is driven to draw air in the portablecomputer 70. However, air cooled in the deskstation 80 may be exhaustedinto the portable computer 70.

[0413] In addition, the computer system can also have a structure inwhich the sensors are arranged in the portable computer 70, and signalsrepresenting values detected by the sensors are sent to the deskstation80 through, e.g., the communication connector shown in the first orsecond embodiment, thereby executing the above control in thedeskstation 80. In this case, the function of the drive controller maybe provided to a deskstation controller for controlling the entiredeskstation.

[0414] The second example of the fifth embodiment will be describedbelow with reference to FIGS. 34A and 34B.

[0415] A computer system shown in FIGS. 34A and 34B is also constitutedby a portable computer 70A and a deskstation 80A used to expand thefunction of the portable computer 70A. As in the first example, thedeskstation has a fan. However, in the deskstation 80A, the fan isarranged below a position where the portable computer is loaded andsends cooled air into the portable computer.

[0416]FIG. 34B shows the structure of the computer system of the secondexample. As shown in FIG. 34B, the portable computer 70A has exhaustports 71A in both the side surfaces of the main body and the exhaustport 72 on the rear surface. A suction port 73 for drawing cooled airblown from the deskstation 80A is formed in the bottom surface of theportable computer 70A. The deskstation 80A used to expand the functionof the portable computer 70A has the sensors (S) 81 a and 81 b, a fan82A, and a drive controller 83A, as in the first example. Thedeskstation 80A also has a suction port 84A in its bottom surface, andan exhaust port 85A for exhausting the cooled air in a surface whichcontacts the bottom surface of the portable computer 70A upon connectionto the portable computer 70A. When the portable computer 70A is loadedin (connected to) the deskstation 80A, the exhaust port 73 of theportable computer 70A contacts the suction port 85A of the deskstation80A to oppose each other.

[0417] The sensors 81 a and 81 b detect the temperatures of the CPU chip(CPU board) incorporated in the portable computer 70A mounted in thedeskstation 80A. Two sensors are provided in this embodiment. However,for the purpose of cooling the CPU chip, only one sensor may besufficiently arranged near the CPU chip. The fan 82A blows external airdrawn from the suction port 84A, or cooled air if a mechanism forcooling the air is arranged, into the portable computer 70A under thecontrol of the drive controller 83A. The drive controller 83A controlsthe fan 82A in accordance with detection signals from the sensors 81 aand 81 b, thereby exchanging air in the portable computer 70A, which isheated by the heat generating portion such as the CPU chip and the CPUboard. With this operation, when the portable computer 70A is mounted inthe deskstation 80A serving-as a function expansion unit, degradation inheat dissipation of the portable computer 70A can be covered, therebymaintaining a reliable function expansion operation.

[0418] An operation in this structure is the same as that of the firstexample, and a detailed description thereof will be omitted. With thiscooling mechanism of the portable computer, degradation in heatdissipation of the portable computer 70A mounted in the deskstation 80Acan be covered, thereby maintaining a reliable function expansionoperation. The fan 82A may be driven to draw air in the portablecomputer 70A, as in the first example.

[0419] In addition, the computer system can also have a structure inwhich the sensors are arranged in the portable computer 70A, and signalsrepresenting values detected by the sensors are sent to the deskstation80A through, e.g., the communication connector shown in the first orsecond embodiment, thereby executing the above drive control in thedeskstation 80A.

[0420] Some variations of temperature detection of the CPU chip intemperature control shown in the first and second examples will bedescribed below.

[0421] The first variation is shown in FIG. 35. Referring to FIG. 35, aCPU board 710 has the mounting circuit pattern of a CPU. A CPU chip 711is mounted at the CPU mounting position of the CPU board 710.

[0422] A temperature sensor (S) 712 is directly attached to the CPU chip711 and directly detects the temperature of the heat generating portionof the CPU chip 711.

[0423] An air-cooling fan 713 blows cooled air to the CPU chip 711. Afan drive controller (DRV) 714 drives and controls the air-cooling fan713 on the basis of a detection signal from the temperature sensor (S)712.

[0424] When the detection temperature from the temperature sensor (S)712 amounts to a set value, the fan drive controller (DRV) 714 drivesthe air-cooling fan 713 to blow cooled air to the CPU chip 711.

[0425] In the above structure, the surface temperature of the CPU chip711 is detected by the temperature sensor (S) 712, and a detectionsignal is supplied to'the fan drive controller (DRV) 714.

[0426] When the detection temperature from the temperature sensor (S)712 amounts to the set temperature, the fan drive controller (DRV) 714drives the air-cooling fan 713 to blow cooled air to the CPU chip 711.The fan drive controller (DRV) 714 may also drive the fan 713 to drawand exhaust air heated by the CPU 711, as shown in the first example.

[0427] With the structure in which the fan 713 for cooling the CPU chip711 is directly driven and controlled on the basis of the detectionsignal from the temperature sensor (S) 712 directly attached to the CPUchip 711, the temperature of the CPU chip 711 can be immediately (i.e.,with a largely shortened delay time) reflected on cooling control of theCPU chip 711. Therefore, the performance of the CPU chip 711 can besufficiently used to realize a high-speed operation of the CPU chip atan almost threshold frequency.

[0428] The second variation is shown in FIG. 36. Referring to FIG. 36, aCPU board 720 has the mounting circuit pattern of a CPU. A CPU chip 721is mounted at the CPU mounting position of the CPU board 720.

[0429] A temperature sensor (S) 722 is arranged at the CPU chip mountingportion of the CPU chip 721 and, directly detects the temperature of theheat generating portion of the chip from the lower surface of the CPUchip 721.

[0430] An air-cooling fan 723 blows cooled air to the CPU chip 721. Afan drive controller (DRV) 724 drives and controls the air-cooling fan723 on the basis of a detection signal from the temperature sensor (S)722.

[0431] When the detection temperature from the temperature sensor (S)722 amounts to a set value, the fan drive controller (DRV) 724 drivesthe air-cooling fan 723 to blow cooled air to the CPU chip 721.

[0432] In the above structure, the temperature of the CPU chip 721 isdetected by the temperature sensor (S) 722, and a detection signal issupplied to the fan drive controller (DRV) 724.

[0433] When the detection temperature from the temperature sensor (S)722 amounts to the set temperature, the fan drive controller (DRV) 724drives the air-cooling fan 723 to blow cooled air to the CPU chip 721.

[0434] With the structure in which the fan 723 for cooling the CPU chip721 is directly driven and controlled on the basis of the detectionsignal from the temperature sensor (S) 722 directly attached to the CPUchip 721, the temperature of the CPU chip 721 can be immediately (i.e.,with a largely shortened delay time) reflected on cooling control of theCPU chip 721. Therefore, the performance of the CPU chip 721 can besufficiently used to realize a high-speed operation of the CPU chip atan almost threshold frequency.

[0435] The third variation is shown in FIG. 37. Referring to FIG. 37, aCPU board 730 has the mounting circuit pattern of a CPU. A CPU chip 731is mounted at the CPU mounting position of the CPU board 730, and fins(F) for radiating the heat of the chip are arranged at the upper surfaceportion of the chip.

[0436] A temperature sensor (S) 732 is directly attached to the fins (F)of the CPU chip 731 and directly detects the temperature of the heatgenerating portion of the CPU chip 731 by directly measuring thetemperature of the fins (F).

[0437] An air-cooling fan 733 blows cooled air to the CPU chip 731. Afan drive controller (DRV) 734 drives and controls the air-cooling fan733 on the basis of a detection signal from the temperature sensor (S)732.

[0438] When the detection temperature from the temperature sensor (S)732 amounts to a set value, the fan drive controller (DRV) 734 drivesthe air-cooling fan 733 to blow cooled air to the CPU chip 731.

[0439] In the above structure, the temperature of the CPU chip 731 isdetected by the temperature sensor (S) 732, and a detection signal issupplied to the fan drive controller (DRV) 734.

[0440] When the detection temperature from the temperature sensor (S)732 amounts to the set temperature, the fan drive controller (DRV) 734drives the air-cooling fan 733 to blow cooled air to the CPU chip 731.

[0441] With the structure in which the fan 733 for cooling the CPU chip731 is directly driven and controlled on the basis of the detectionsignal from the temperature sensor (S) 732 directly attached to the fins(F) for radiating the heat of the CPU chip 731, the temperature of theCPU chip 731 can be immediately reflected on cooling control of the CPUchip 731. Therefore, the performance of the CPU chip 731 can besufficiently used to realize a high-speed operation of the CPU chip atan almost threshold frequency.

[0442] The fourth variation is shown in FIG. 38. Referring to FIG. 38, aCPU board 740 has the mounting circuit pattern of a CPU. A CPU chip 741is mounted at the CPU mounting position of the CPU board 740, and athermal conductor (H) for transmitting the heat generated in the chip isarranged at the upper surface portion of the chip.

[0443] A temperature sensor (S) 742 is directly attached to the thermalconductor (H) of the CPU chip 741 and directly detects the temperatureof the heat generating portion of the CPU chip 741 by directly measuringthe temperature of the thermal conductor (H).

[0444] An air-cooling fan 743 blows cooled air to the CPU chip 741. Afan drive controller (DRV) 744 drives and controls the air-cooling fan743 on the basis of a detection signal from the temperature sensor (S)742.

[0445] When the detection temperature from the temperature sensor (S)742 amounts to a set value, the fan drive controller (DRV) 744 drivesthe air-cooling fan 743 to blow cooled air to the CPU chip 741.

[0446] In the above structure, the temperature of the CPU chip 741 isdetected by the temperature sensor (S) 742, and a detection signal issupplied to the fan drive controller (DRV) 744.

[0447] When the detection temperature from the temperature sensor (S)742 amounts to the set temperature, the fan drive controller (DRV) 744drives the air-cooling fan 743 to blow cooled air to the CPU chip 741.

[0448] With the structure in which the fan 743 for cooling the CPU chip741 is directly driven and controlled on the basis of the detectionsignal from the temperature sensor (S) 742 directly attached to thethermal conductor (H) of the CPU chip 741, the temperature of the CPUchip 741 can be immediately reflected on cooling control of the CPU chip741. Therefore, the performance of the CPU chip 741 can be sufficientlyused to realize a high-speed operation of the CPU chip at an almostthreshold frequency.

[0449] Variations related to CPU temperature detection in the clockcontrol of the fourth embodiment will be described below. The followingfifth to eighth variations correspond to the above-described fourvariations, respectively.

[0450] The fifth variation is shown in FIG. 39. Referring to FIG. 39, aCPU board 810 has the mounting circuit pattern of a CPU. A CPU chip 811is mounted at the CPU mounting position of the CPU board 810. The CPUchip 811 is directly mounted at the CPU mounting position of the CPUboard 810 through a CPU connector by soldering or the like.

[0451] A temperature sensor (S) 812 is directly attached to the CPU chip811 and directly measures the temperature of the heat generating portionon the upper surface of the CPU chip 811.

[0452] A clock generator (CLK-GEN) 813 supplies an operating clock (CPUclock) to the CPU chip 811 and controls the CPU clock frequency on thebasis of a detection signal from the temperature sensor (S) 812. Whenthe detection temperature from the temperature sensor (S) 812 increasesbeyond a set temperature, the CPU clock frequency is lowered inaccordance with the increase in temperature.

[0453] A circuit 814 supplies the CPU clock to the CPU chip 811. Thecircuit 814 supplies the CPU clock generated by the clock generator(CLK-GEN) 813 to the clock input terminal (Tc) of the CPU chip 811.

[0454] In the above structure, the temperature sensor (S) 812 directlyattached to the CPU chip 811 directly measures the temperature of theheating portion on the upper surface of the CPU 811 and supplies atemperature detection signal to the clock generator (CLK-GEN) 813.

[0455] The clock generator (CLK-GEN) 813 monitors the temperature of theCPU chip 811 on the basis of the detection signal from the temperaturesensor (S) 812. When the temperature of the CPU chip 811 is lower thanthe set temperature, a CPU clock having a predetermined definedfrequency is supplied to the clock input terminal (Tc) of the CPU chip811 through the clock supplying circuit 814.

[0456] Thereafter, when the temperature of the CPU chip 811 increasesbeyond the set temperature, the clock generator (CLK-GEN) 813 controlsthe CPU clock frequency on the basis of the detection signal from thetemperature sensor (S) 812. More specifically, when the detectiontemperature from the temperature sensor (S) 812 increases beyond the settemperature, the CPU clock frequency is lowered in accordance with theincrease in temperature. The CPU clock is supplied to the clock inputterminal (Tc) of the CPU chip 811 through the clock supplying circuit814.

[0457] Since the CPU clock frequency supplied to the CPU chip 811 iscontrolled on the basis of the detection signal from the temperaturesensor (S) 812 directly attached to the CPU chip 811, the temperature ofthe CPU chip 811 can be immediately (i.e., accurately without any timedelay) reflected on temperature control by clock frequency control ofthe CPU chip 811. Therefore, the performance of the CPU chip 811 can besufficiently used to realize a high-speed operation of the CPU chip 811at an almost threshold frequency.

[0458] The sixth variation will be described below with reference toFIG. 40. Referring to FIG. 40, a CPU board 820 has the mounting circuitpattern of a CPU. A CPU chip 821 is mounted at the CPU mounting positionof the CPU board 820.

[0459] A temperature sensor (S) 822 is arranged at the CPU chip mountingportion of the CPU board 820. The temperature sensor (S) 822 measuresthe temperature of the heat generating portion on the lower surface ofthe CPU chip 821 directly or in a closest range.

[0460] A clock generator (CLK-GEN) 823 supplies an operating clock (CPUclock) to the CPU chip 821 and controls the CPU Clock frequency on thebasis of a detection signal from the temperature sensor (S) 822. Whenthe detection temperature from the temperature sensor (S) 822 increasesbeyond a set temperature, the CPU clock frequency is lowered inaccordance with the increase in temperature.

[0461] A circuit 824 supplies the CPU clock to the CPU chip 821. Thecircuit 824 supplies the CPU clock generated by the clock generator(CLK-GEN) 823 to the clock input terminal (Tc) of the CPU chip 821.

[0462] In the above structure, the temperature sensor (S) 822 arrangedat the CPU chip mounting portion of the CPU chip 821 measures thetemperature of the heating portion on the lower surface of the CPU 821directly or in a closest range and supplies a temperature detectionsignal to the clock generator (CLK-GEN) 823.

[0463] The clock generator (CLK-GEN) 823 monitors the temperature of theCPU chip 821 on the basis of the detection signal from the temperaturesensor (S) 822. When the temperature of the CPU chip 821 is lower thanthe set temperature, a CPU clock having a predetermined definedfrequency is supplied to the clock input terminal (Tc) of the CPU chip821 through the clock supplying circuit 824.

[0464] Thereafter, when the temperature of the CPU chip 821 increasesbeyond the set temperature, the clock generator (CLK-GEN) 823 controlsthe CPU clock frequency on the basis of the detection signal from thetemperature sensor (S) 822. More specifically, when the detectiontemperature from the temperature sensor (S) 822 increases beyond the settemperature, the CPU clock frequency is lowered accordingly. The CPUclock is supplied to the clock input terminal (Tc) of the CPU chip 821through the clock supplying circuit 824.

[0465] Since the CPU clock frequency supplied to the CPU chip 821 iscontrolled on the basis of the detection signal from the temperaturesensor (S) 822 provided at the CPU chip mounting portion of the CPUboard 820, the temperature of the CPU chip 821 can be immediately (i.e.,accurately without any time delay) reflected on temperature control byclock frequency control of the CPU chip 821. Therefore, the performanceof the CPU chip 821 can be sufficiently used to realize a high-speedoperation of the CPU chip 821 at an almost threshold frequency.

[0466] The seventh variation will be described below with reference toFIG. 41. Referring to FIG. 41, a CPU board 830 has the mounting circuitpattern of a CPU. A CPU chip 831 is mounted at the CPU mounting positionof the CPU board 830, and the fins (F) for radiating heat generated inthe chip are arranged at the upper surface portion of the chip.

[0467] A temperature sensor (S) 832 is directly attached to the fins (F)of the CPU chip 831. The temperature sensor (S) 832 detects thetemperature of the heat generating portion of the CPU chip 831 bydirectly measuring the temperature of the fins (F).

[0468] A clock generator (CLK-GEN) 833 supplies an operating clock (CPUclock) to the CPU chip 831 and controls the CPU clock frequency on thebasis of a detection signal from the temperature sensor (S) 832. Whenthe detection temperature from the temperature sensor (S) 832 increasesbeyond a set temperature, the CPU clock frequency is lowered inaccordance with the increase in temperature.

[0469] A circuit 834 supplies the CPU clock to the CPU chip 831. Thecircuit 834 supplies the CPU clock generated by the clock generator(CLK-GEN) 833 to the clock input terminal (Tc) of the CPU chip 831.

[0470] In the above structure, the temperature sensor (S) 832 directlyattached to the fins (F) of the CPU chip 831 detects the temperature ofthe heat generating portion of the CPU chip 831 by directly measuringthe temperature of the fin (F) and supplies a temperature detectionsignal to the clock generator (CLK-GEN) 833.

[0471] The clock generator (CLK-GEN) 833 monitors the temperature of theCPU chip 831 on the basis of the detection signal from the temperaturesensor (S) 832. When the temperature of the CPU chip 831 is lower thanthe set temperature, a CPU clock having a predetermined definedfrequency is supplied to the clock input terminal (Tc) of the CPU chip831 through the clock supplying circuit 834.

[0472] Thereafter, when the temperature of the CPU chip 831 increasesbeyond the set temperature, the clock generator (CLK-GEN) 833 controlsthe CPU clock frequency on the basis of the detection signal from thetemperature sensor (S) 832. More specifically, when the detectiontemperature from the temperature sensor (S) 832 increases beyond the settemperature, the CPU clock frequency is lowered in accordance with theincrease in temperature. The CPU clock is supplied to the clock inputterminal (Tc) of the CPU chip 831 through the clock supplying circuit834.

[0473] Since the CPU clock frequency supplied to the CPU chip 831 iscontrolled on the basis of the detection signal from the temperaturesensor (S) 832 directly attached to the fins (F) of the CPU chip 831,the temperature of the CPU chip 831 can be immediately (i.e., accuratelywith a largely shortened delay time) reflected on temperature control byclock frequency control of the CPU chip 831. Therefore, the performanceof the CPU chip 831 can be sufficiently used to realize a high-speedoperation of the CPU chip 831 at an almost threshold frequency.

[0474] The eighth variation will be described below with reference toFIG. 42. Referring to FIG. 42, a CPU board 840 has the mounting circuitpattern of a CPU. A CPU chip 841 is mounted at the CPU mounting positionof the CPU board 840, and the thermal conductor (H) for transmittingheat generated in the chip is arranged at the upper surface portion ofthe chip.

[0475] A temperature sensor (S) 842 is directly attached to the thermalconductor (H). The temperature sensor (S) 842 detects the temperature ofthe heat generating portion of the CPU chip 841 by directly measuringthe temperature of the thermal conductor (H).

[0476] A clock generator (CLK-GEN) 843 supplies an operating clock (CPUclock) to the CPU chip 841 and controls the CPU clock frequency on thebasis of a detection signal from the temperature sensor (S) 842. Whenthe detection temperature from the temperature sensor (S) 842 increasesbeyond a set temperature, the CPU clock frequency is lowered inaccordance with the increase in temperature.

[0477] A circuit 844 supplies the CPU clock to the CPU chip 841. Thecircuit 844 supplies the CPU clock generated by the clock generator(CLK-GEN) 843 to the clock input terminal (Tc) of the CPU chip 841.

[0478] In the above structure, the temperature sensor (S) 842 directlyattached to the thermal conductor (H) detects the temperature of theheat generating portion of the CPU chip 841 by directly measuring thetemperature of the thermal conductor (H) and supplies a detection signalto the clock generator (CLK-GEN) 843.

[0479] The clock generator (CLK-GEN) 843 monitors the temperature of theCPU chip 841 on the basis of the detection signal from the temperaturesensor (S) 842. When the temperature of the CPU chip 841 is lower thanthe set temperature, a CPU clock having a predetermined definedfrequency is supplied to the clock input terminal (Tc) of the CPU chip841.

[0480] Thereafter, when the temperature of the CPU chip 841 increasesbeyond the set temperature, the clock generator (CLK-GEN) 843 controlsthe CPU clock frequency on the basis of a temperature represented by thedetection signal from the temperature sensor (S) 842. More specifically,when the detection temperature from the temperature sensor (S) 842increases beyond the set temperature, the CPU clock frequency is loweredin accordance with the increase in temperature.

[0481] The CPU clock is supplied to the clock input terminal (Tc) of theCPU chip 841 through the clock supplying circuit 844.

[0482] Since the CPU clock frequency supplied to the CPU chip 841 iscontrolled on the basis of the detection signal from the temperaturesensor (S) 842 directly attached to the thermal conductor (H) fortransmitting the heat generated in the CPU chip 841, the temperature ofthe CPU chip 841 can be immediately (i.e., accurately with a largelyshortened delay time) reflected on temperature control by clockfrequency control of the CPU chip 841. Therefore, the performance of theCPU chip 841 can be sufficiently used to realize a high-speed operationof the CPU chip 841 at an almost threshold frequency.

[0483] A modification according to the fifth embodiment will bedescribed below with reference to FIG. 43. In this modification, in aportable computer having a suspend/resume function, the temperature of aCPU chip is detected by a temperature sensor. When the temperaturesensor detects an operating limitation temperature of the CPU chip,suspend processing is executed.

[0484] Referring to FIG. 43, a CPU (CPU chip) 91 controls the entiresystem and is connected to a main memory (MEM) 94, a storage memory 96,and various input/output devices (I/O) through a system bus.

[0485] A temperature sensor (S) 92 measures the chip temperature of theCPU 91. As an example, the temperature sensor (S) 92 is directlyattached to the chip, as shown in the first and second examples.

[0486] An interrupt generation unit (IRG) 93 monitors the detectiontemperature from the temperature sensor (S) 92 and generates a forcedinterrupt when the detection temperature amounts to a predeterminedoperating limitation temperature. When the chip temperature of the CPU91 amounts to the operating limitation temperature, a forced interruptis generated to the CPU 91.

[0487] A suspend/resume processing unit (S/R) 95 is resident in the mainmemory (MEM) 94. When the suspend/resume processing unit (S/R) 95 is setin a resume mode by setup, it is started in accordance with the ON/OFFoperation of the power supply.

[0488] The suspend/resume function itself is the same as that of anormal personal computer. In this embodiment, however, when a forcedinterrupt is generated by the interrupt generation unit (IRG) 93independently of the set contents of the resume mode, the suspend/resumeprocessing unit is forcibly started to execute suspend processing. Uponcompletion of the suspend processing, the power supply is turned off(powered off). Thereafter, when the power supply is turned on (poweredon), resume processing is executed to restore a processing state at thetime of interrupt so that the processing before the interrupt can becontinued.

[0489] In the above structure, the temperature sensor (S) 92 measuresthe chip temperature of the CPU 91 and supplies a temperature detectionsignal to the interrupt generation unit (IRG) 93.

[0490] The interrupt generation unit (IRG) 93 monitors the detectiontemperature from the temperature sensor (S). 92. When the detectiontemperature amounts to a predetermined operating limitation temperature,a forced interrupt is generated to the CPU 91.

[0491] Upon reception of the forced interrupt from the interruptgeneration unit (IRG) 93, the CPU 91 ends the processing in anappropriate step and starts the suspend/resume processing unit (S/R) 95to execute suspend processing. Data obtained in the suspend processingis stored in the storage memory 96.

[0492] As described above, when the chip temperature of the CPU 91amounts to a high temperature which does not allow continuation of anormal operation, suspend processing is executed. With this processing,when a state for maintaining the normal operation is attained, aprocessing state at the time of interrupt can be restored to continuethe processing. Therefore, a reliable operation can be maintained.

[0493] The second modification according to the fifth embodiment will bedescribed below with reference to FIG. 44. This modification is acombination of the above-described second and third variations. In thesecond modification, a temperature sensors 912 arranged at the CPU chipmounting portion of a CPU board 910 measures the temperature of the heatgenerating portion on the lower surface of a CPU chip 911 directly or ina closest range and supplies a temperature detection signal to a clockgenerator (CLK-GEN) 913 and a fan drive controller (DRV) 914.

[0494] The clock generator (CLK-GEN) 913 monitors the temperature of theCPU chip 911 on the basis of the detection signal from the temperaturesensor (S) 912. When the temperature of the CPU chip 911 is lower than aset temperature, a CPU clock having a predetermined defined frequency issupplied to the clock input terminal (Tc) of the CPU chip 911 throughthe clock generator 913.

[0495] The fan drive controller (DRV) 914 monitors the temperature ofthe CPU chip 911 on the basis of the detection signal from thetemperature sensor (S) 912. When the temperature of the CPU chip 911 islower than a set temperature, a fan 915 is set in a stop state.

[0496] Thereafter, when the detection temperature from the temperaturesensor (S) 912 amounts to the set temperature, the fan drive controller(DRV) 914 drives the fan 915 to blow cooled air to the CPU chip 911.

[0497] When the temperature of the CPU chip 911 increases beyond the settemperature, the clock generator (CLK-GEN) 913 controls the CPU clockfrequency on the basis of the detection signal from the temperaturesensor (S) 912. More specifically, when the detection temperature fromthe temperature sensor (S) 912 increases, the CPU clock frequency islowered accordingly. The CPU clock is supplied to the clock inputterminal (Tc) of the CPU chip 911 through the clock generator 913.

[0498] The set temperature of the fan drive controller (DRV) 914 is setlower than that of the clock generator (CLK-GEN) 913. In this case, thefan 915 is driven to cool the CPU chip 911 before the clock generator(CLK-GEN) 913 retards the CPU clock. For this reason, a high-speedoperation of the CPU chip can be performed at an almost thresholdfrequency for a long time. When the set temperature of the fan drivecontroller (DRV) 914 is set to be equal to that of the clock generator(CLK-GEN) 913, cooling by the fan 915 and retardation of the CPU clockare simultaneously started, thereby restoring the high-speed CPU clockstate within a short time.

[0499] In the above examples except for the first and second examples,only one temperature sensor is arranged. However, a plurality oftemperature sensors may also be separately arranged. In this case, asfor positions where the temperature sensors are arranged, the abovevariations may be combined with each other or another position (e.g., onthe inner wall of the housing) may also be combined.

[0500] As described above in detail, according to the fifth embodiment,air heated by a heat generating portion in the portable computer isdrawn on the deskstation side, or cooled air is blown from thedeskstation side, thereby enabling appropriate temperature control.Therefore, the performance of the CPU chip can be sufficiently used torealize a high-speed operation of the CPU chip at an almost thresholdfrequency. In addition, since the fan is arranged on the deskstationside, the size of the portable computer can be further reduced.

[0501] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a circuit for supplying a clock to aCPU chip, a temperature sensor directly attached to the CPU chip, and acircuit for controlling the clock frequency on the basis of a detectionsignal from the temperature sensor. The clock frequency supplied to theCPU chip is controlled on the basis of the detection signal from thetemperature sensor directly attached to the CPU chip. With thisstructure, the temperature of the CPU chip can be directly reflected onchip temperature control by clock frequency control. For this reason,the performance of the CPU chip can be sufficiently used to realize ahigh-speed operation of the CPU chip at an almost threshold frequency.

[0502] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a circuit for supplying a clock to aCPU chip, a temperature sensor arranged at the CPU chip mounting portionof the CPU board, and a circuit for controlling the clock frequency onthe basis of a detection signal from the temperature sensor. The clockfrequency supplied to the CPU chip is controlled on the basis of thedetection signal from the temperature sensor arranged at the CPU chipmounting portion of the CPU board. With this structure, the temperatureof the CPU chip can be immediately reflected on chip temperaturecontrol. For this reason, the performance of the CPU chip can besufficiently used to realize a high-speed operation of the CPU chip atan almost threshold frequency.

[0503] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a circuit for supplying a clock to aCPU chip, fins for radiating the heat of the CPU chip, a temperaturesensor provided to the fins, and a circuit for controlling the clockfrequency on the basis of a detection signal from the temperaturesensor. The clock frequency supplied to the CPU chip is controlled onthe basis of the detection signal from the temperature sensor providedto the fins of the CPU chip. With this structure, the temperature of theCPU chip can be immediately reflected to chip temperature control. Forthis reason, the performance of the CPU chip can be sufficiently used torealize a high-speed operation of the CPU chip at an almost thresholdfrequency.

[0504] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a circuit for supplying a clock to aCPU chip, a thermal conductor for transmitting the heat of the CPU chip,a temperature sensor for detecting the temperature of the CPU chipthrough the thermal conductor, and a circuit for controlling the clockfrequency on the basis of a detection signal from the temperaturesensor. The clock frequency supplied to the CPU chip is controlled onthe basis of the detection signal from the temperature sensor providedto the thermal conductor for transmitting the heat of the CPU chip. Withthis structure, the temperature of the CPU chip can be immediatelyreflected on chip temperature control. For this reason, the performanceof the CPU chip can be sufficiently used to realize a high-speedoperation of the CPU chip at an almost threshold frequency.

[0505] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a fan for cooling a CPU chip, atemperature sensor directly attached to the CPU chip, and a circuit fordriving and controlling the fan on the basis of a detection signal fromthe temperature sensor. The fan for cooling the CPU chip is driven andcontrolled on the basis of the detection signal from the temperaturesensor directly attached to the CPU chip. With this structure, thetemperature of the CPU chip can be directly reflected on chiptemperature control. For this reason, the performance of the CPU chipcan be sufficiently used to realize a high-speed operation of the CPUchip at an almost threshold frequency.

[0506] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a fan for cooling a CPU chip, atemperature sensor arranged at the CPU chip mounting portion of the CPUboard, and a circuit for driving and controlling the fan on the basis ofa detection signal from the temperature sensor. The fan for cooling theCPU chip is driven and controlled on the basis of the detection signalfrom the temperature sensor arranged at the CPU chip mounting portion ofthe CPU board. With this structure, the temperature of the CPU chip canbe immediately reflected on chip temperature control. For this reason,the performance of the CPU chip can be sufficiently used to realize ahigh-speed operation of the CPU chip at an almost threshold frequency.

[0507] According to this embodiment, an electronic equipmentincorporating a CPU board comprises fins for radiating the heat of a CPUchip, a temperature sensor provided to the fins, a fan for cooling theCPU chip through the fins, and a circuit for driving and controlling thefan on the basis of a detection signal from the temperature sensor. Thefan for cooling the CPU chip is driven and controlled on the basis ofthe detection signal from the temperature sensor provided to the fins ofthe CPU chip. With this structure, the temperature of the CPU chip canbe immediately reflected on chip temperature control. For this reason,the performance of the CPU chip can be sufficiently used to realize ahigh-speed operation of the CPU chip at an almost threshold frequency.

[0508] According to this embodiment, an electronic equipmentincorporating a CPU board comprises a thermal conductor for transmittingthe heat of a CPU chip, a temperature sensor for detecting thetemperature of the CPU chip through the thermal conductor, a fan forcooling the CPU chip through the thermal conductor, and a circuit fordriving and controlling the fan on the basis of a detection signal fromthe temperature sensor. The fan for cooling the CPU chip is driven andcontrolled on the basis of the detection signal from the temperaturesensor provided to the thermal conductor of the CPU chip. With thisstructure, the temperature of the CPU chip can be immediately reflectedon chip temperature control. For this reason, the performance of the CPUchip can be sufficiently used to realize a high-speed operation of theCPU chip at an almost threshold frequency.

[0509] According to this embodiment, a portable computer having asuspend/resume function comprises a temperature sensor for detecting thetemperature of a CPU chip, and a control means for executing suspendprocessing on the basis of a detection signal from the temperaturesensor. When the temperature of the CPU chip amounts to a hightemperature which does not allow continuation of a normal operation,suspend processing is executed. With this processing, when a state formaintaining the normal operation is attained, a processing stateinterrupted upon execution of forced suspend processing can be restored.For this reason, a reliable operation can be maintained.

[0510] According to this embodiment, a function expansion unit forexpanding the function of a portable computer comprises a sensor fordetecting the temperature of a chip incorporated in the portablecomputer mounted in the unit, a fan and air blow port for blowing cooledair to the mounted portable computer, and a control means for drivingand controlling the fan on the basis of a detection signal from thetemperature sensor. With this structure, degradation in heat dissipationof the portable computer mounted in the function expansion unit can becovered, thereby maintaining a reliable function expansion operation.

[0511] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details, representative devices,and illustrated examples shown and described herein. Accordingly,various modifications may be made without departing from the spirit orscope of the general inventive concept as defined by the appended claimsand their equivalents.

What is claimed is:
 1. A computer system comprising: a computer havingfirst and second connectors, a bus, and connection control means forenabling/disabling connection between said second connector and saidbus; and an expansion unit capable of being attached/detached to/fromsaid computer, wherein said expansion unit has a third connectorconnectable to said first connector and connected to said firstconnector when said computer is set at a mounting position of saidexpansion unit, a fourth connector connectable to said second connectorand arranged to be free to move between a first position where saidfourth connector is disconnected from said second connector and a secondposition where said fourth connector is connected to said secondconnector when said computer is set at the mounting position, at leastone expansion connector connected to said fourth connector and capableof being mounted with an expansion device, a loading mechanism formoving said fourth connector between the first position and the secondposition, and expansion unit control means for outputting a connectionrequest signal for connection between said second connector and saidfourth connector to said computer through said third connector when saidcomputer is set at the mounting position, moving said fourth connectorfrom the first position to the second position by driving said loadingmechanism in accordance with a permission signal sent from said firstconnector, and outputting a connection completion signal upon completionof movement of said fourth connector to said second position, saidconnection control means is set to disable connection between saidsecond connector and said bus in advance, and said computer includescomputer control means for outputting the permission signal to saidexpansion unit through said first connector in accordance with theconnection request signal, and controlling said connection control meansto enable connection between said second connector and said bus whensaid computer is in a power ON state upon reception of the connectionrequest signal.
 2. A system according to claim 1, wherein said expansionunit control means includes means for applying an operating voltage tosaid expansion device connected to said expansion connector when saidcomputer is in a power ON state.
 3. A system according to claim 1,wherein said expansion unit control means includes a sensor fordetecting that said computer is set at the mounting position.
 4. Asystem according to claim 1, wherein said expansion unit control meansdetects that said computer is set at the mounting position by monitoringa voltage of a predetermined pin of said third connector.
 5. A systemaccording to claim 1, wherein said computer includes means for readingattribute information of said expansion device from said expansion unitand setting a system environment for use of said expansion unit inaccordance with the attribute information.
 6. A system according toclaim 1, wherein said expansion unit includes an eject switch fordesignating to detach said fourth connector of said expansion unit fromsaid second connector, and means for sending a detachment request signalfor detachment of said fourth connector to said computer through saidthird connector when said eject switch designates to detach said fourthconnector from said second connector, moving said fourth connector fromthe second position to the first position by driving said loadingmechanism in accordance with the detachment request signal sent fromsaid computer, and outputting a separation completion signal uponcompletion of movement of said fourth connector to the first position,and said computer includes means for, when said computer is in a powerON state, controlling said connection control means to enable connectionbetween said second connector and said bus in accordance with thedetachment request signal and outputting a detachment permission signalthrough said first connector.
 7. A system according to claim 6, whereinsaid expansion unit includes means for stopping applying an operatingvoltage to said expansion device connected to said expansion connectorin accordance with the detachment permission signal.
 8. A systemaccording to claim 6, wherein said computer includes means fordetermining in accordance with the detachment request signal whethersaid expansion device connected to said expansion connector is beingused, outputting the detachment permission signal when said expansiondevice is not being used, and stopping outputting the detachmentpermission signal when said expansion device is being used.
 9. A systemaccording to claim 8, wherein said computer includes means for informingan operator that said expansion device connected to said expansionconnector is being used when it is determined that said expansion deviceis being used.
 10. A system according to claim 6, wherein said computerincludes means for outputting the detachment permission signal inaccordance with the detachment request signal when said computer is in apower OFF state.
 11. A computer system comprising: a computer having afirst connector, a bus, a second connector connected to said bus, and anonvolatile memory; and an expansion unit capable of beingattached/detached to/from said computer, wherein said expansion unit hasa third connector connectable to said first connector and connected tosaid first connector when said computer is set at a mounting position ofsaid expansion unit, a fourth connector connectable to said secondconnector and arranged to be free to move between a first position wheresaid fourth connector is disconnected from said second connector and asecond position where said fourth connector is connected to said secondconnector when said computer is set at the mounting position, at leastone expansion connector connected to said fourth connector and capableof being mounted with an expansion device, a loading mechanism formoving said fourth connector between the first position and the secondposition, and expansion unit control means for, when said computer isset at the mounting position, outputting a connection request signal forconnection between said second connector and said fourth connector tosaid computer through said third connector and moving said fourthconnector from the first position to the second position by driving saidloading mechanism in accordance with a permission signal sent from saidfirst connector, and said computer includes computer control means for,when said computer is in a power ON state, executing suspend processingin which information necessary for resuming processing which is beingexecuted is stored in said nonvolatile memory to interrupt theprocessing and set a power OFF state in accordance with the connectionrequest signal and thereafter outputting the permission signal to saidexpansion unit through said first connector.
 12. A system according toclaim 11, wherein said expansion unit control means includes means foroutputting a connection completion signal upon completion of movement ofsaid fourth connector to the second position, and said computer controlmeans includes means for executing resume processing in which theinformation stored in said nonvolatile memory is used to resume theinterrupted processing when the suspend processing is being executedupon reception of the connection completion signal.
 13. A systemaccording to claim 12, wherein said expansion unit includes means forstarting applying an operating voltage to said expansion deviceconnected to said expansion connector when said computer in a power OFFstate is set in a power ON state.
 14. A system according to claim 11,wherein said expansion unit control means includes a sensor fordetecting that said computer is set at the mounting position.
 15. Asystem according to claim 11, wherein said expansion unit control meansdetects that said computer is set at the mounting position by monitoringa voltage of a predetermined pin of said third connector.
 16. A systemaccording to claim 11, wherein said computer includes means for readingattribute information of said expansion device from said expansion unitand setting a system environment for use of said expansion unit inaccordance with the attribute information.
 17. A system according toclaim 12, wherein said expansion unit includes an eject switch fordesignating to detach said fourth connector of said expansion unit fromsaid second connector, and means for sending a detachment request signalfor detachment of said fourth connector to said computer through saidthird connector when said eject switch designates to detach said fourthconnector from said second connector, and moving said fourth connectorfrom the second position to the first position by driving said loadingmechanism in accordance with the detachment request signal sent fromsaid computer, and said computer includes means for, when said computeris in a power ON state, executing the suspend processing in accordancewith the detachment request signal and outputting a detachmentpermission signal through said first connector.
 18. A system accordingto claim 17, wherein said expansion unit includes means for stoppingapplying an operating voltage to said expansion device connected to saidexpansion connector in accordance with the detachment permission signal.19. A system according to claim 17, wherein said expansion unit includesmeans for outputting a separation completion signal upon completion ofmovement of said fourth connector to the first position, and saidcomputer includes means for executing resume processing in which theinformation stored in said nonvolatile memory to resume the interruptedprocessing in accordance with the separation completion signal when thesuspend processing is being executed.
 20. A system according to claim17, wherein said computer includes means for determining in accordancewith the detachment request signal whether said expansion deviceconnected to said expansion connector is being used, outputting thedetachment permission signal when said expansion device is not beingused, and stopping outputting the detachment permission signal when saidexpansion device is being used.
 21. A system according to claim 20,wherein said computer includes means for informing an operator that saidexpansion device connected to said expansion connector is being usedwhen it is determined that said expansion device is being used.
 22. Asystem according to claim 21, wherein said computer includes means foroutputting the detachment permission signal in accordance with thedetachment request signal when said computer is in a power OFF state.23. A computer system comprising: a computer; and an expansion unitcapable of being attached/detached to/from said computer and constitutedby an expansion unit main body and a power supply unit, wherein saidpower supply unit is connected to said expansion unit main body througha cable and supplies a first power to said expansion unit through saidcable, and said expansion unit main body includes at least one expansionconnector connectable to an expansion device for expanding a function ofsaid computer, a mounting portion for mounting said computer, and apower supply circuit for supplying an operating power to said expansiondevice on the basis of the first power supplied from said power supplyunit when said computer is mounted at said mounting portion.
 24. Asystem according to claim 23, wherein said expansion unit main bodyincludes means for designating to start/stop supplying the first powerthrough said cable.
 25. A system according to claim 23, wherein saidexpansion unit main body includes means for designating to startsupplying the first power through said cable when said computer ismounted at said mounting portion.
 26. A system according to claim 23,wherein said power supply unit has a plurality of power supply outlets,and said expansion unit main body includes means for enabling saidplurality of power supply outlets in a predetermined order withpredetermined time lags.
 27. A system according to claim 23, whereinsaid computer includes means for designating to start/stop supplying thefirst power through said expansion unit main body and said cable whensaid computer is mounted at said mounting portion.
 28. A systemaccording to claim 27, wherein said expansion unit has a plurality ofpower supply outlets, and said computer includes means for enabling saidplurality of power supply outlets in a predetermined order withpredetermined time lags.
 29. A computer system comprising: a computer;and an expansion unit capable of being attached/detached to/from saidcomputer, wherein said expansion unit includes at least one expansionconnector connectable to an expansion device for expanding a function ofsaid computer, a mounting portion for mounting said computer, and a lockmechanism for fixing said computer at a predetermined position of saidmounting portion when said computer is mounted at said mounting portion.30. A system according to claim 29, wherein said expansion unit has adetachable input device and includes means for operating said lockmechanism when specific information is supplied from said input device.31. A system according to claim 29, wherein said expansion unit has adetachable input device and includes means for releasing said lockmechanism when specific information is supplied from said input device.32. A system according to claim 29, wherein said expansion unit includesmeans for operating said lock mechanism when said computer is mounted.33. A system according to claim 29, wherein said expansion unit has aneject switch for detaching said mounted computer and includes means forreleasing said lock mechanism in accordance with an operation of said iseject switch.
 34. A computer system comprising: a computer having afirst connector connected to a bus and at least one second connectorconnectable to an external device; a relay unit connected to saidcomputer and having a third connector connected to said bus which relayssaid first connector, and at least one fourth connector connectable tosaid external device which relays said second connector; and at leastone expansion unit connectable to said relay unit, wherein saidexpansion unit has a mounting portion capable of being mounted with anexpansion device for expanding a function of said computer, an internalbus connected to said expansion device mounted at said mounting portion,a fifth connector connected to said internal bus, and a sixth connectorconnectable to either said third connector or said fifth connector ofanother expansion unit.
 35. A system according to claim 34, wherein saidfirst and second connectors are arranged on a rear surface of saidcomputer, said relay unit is mounted on said rear surface of saidcomputer so as to have said third connector on a lower surface andrelays said first and second connectors of said computer, and said atleast one expansion unit is mounted under said computer and said relayunit to overlap another expansion unit such that said bus of saidcomputer is connected to said expansion device of said expansion unit.36. An electronic equipment comprising: a processor incorporating adelay circuit element whose delay time changes depending on atemperature; a detection circuit, connected to said delay circuitelement, for detecting an internal temperature of said processor from achange in response delay of said delay circuit element; and clockcontrol means for controlling a clock signal supplied to said processorsuch that an operating speed of said processor is decreased when theinternal temperature detected by said detection circuit exceeds a firsttemperature.
 37. An electronic equipment according to claim 36, furthercomprising a nonvolatile memory, and means for causing said nonvolatilememory to store information necessary for resuming processing which isbeing executed, thereby powering off said electronic equipment when theinternal temperature detected by said detection circuit exceeds a secondtemperature.
 38. An electronic equipment comprising: a processor forcontrolling said electronic equipment; a detection circuit for detectingan internal temperature of said processor; and clock control means forcontrolling a clock signal supplied to said processor such that anoperating speed of said processor is decreased when the internaltemperature detected by said detection circuit exceeds a firsttemperature.
 39. An equipment according to claim 38, further comprisinga nonvolatile memory, and suspend means for causing said nonvolatilememory to store information necessary for resuming processing which isbeing executed, thereby powering off said electronic equipment when theinternal temperature detected by said detection circuit exceeds a secondtemperature.
 40. An equipment according to claim 39, further comprisinga fan for exchanging air in the periphery of said processor, a drivingcircuit for driving said fan, and means for controlling said drivingcircuit to cool the air in the periphery of said processor in accordancewith the internal temperature detected by said detection circuit.
 41. Anequipment according to claim 40, wherein said processor has an elementwhose characteristics change depending on a temperature, and saiddetection circuit detects the internal temperature of said processor onthe basis of a characteristic signal from said element.
 42. An equipmentaccording to claim 40, wherein said processor has a p-n junction circuitelement for temperature detection, and said detection circuit detectsthe internal temperature of said processor on the basis of a signalsupplied from said p-n junction circuit element.
 43. An equipmentaccording to claim 40, wherein said processor has a transistor circuitelement for temperature detection, and said detection circuit detectsthe internal temperature of said processor on the basis of a signalsupplied from said transistor circuit element.
 44. An equipmentaccording to claim 40, wherein said processor has a thermistor circuitelement for temperature detection, and said detection circuit detectsthe internal temperature of said processor on the basis of a signalsupplied from said thermistor circuit element.
 45. An equipmentaccording to claim 40, wherein said processor has a delay circuitelement for temperature detection, and said detection circuit detectsthe internal temperature of said processor on the basis of a signalsupplied from said delay circuit element.
 46. A computer systemcomprising: a computer having a processor for controlling said entirecomputer; an expansion unit used to expand a function of said computerand capable of being attached/detached to/from said computer; and asensor for detecting a temperature of said processor, wherein saidexpansion unit includes a fan for exchanging air in the periphery ofsaid processor, a driving circuit for driving said fan, and controlmeans for appropriately setting the temperature of said processor bycontrolling said driving circuit in accordance with the temperaturedetected by said sensor.
 47. A system according to claim 46, furthercomprising communication means for performing communication between saidcomputer and said expansion unit, and wherein said sensor is arrangednear said processor in said computer and outputs a signal representingthe temperature of said processor to said expansion unit through saidcommunication means.
 48. A system according to claim 46, wherein saidsensor is arranged near a mounting portion of said expansion unit, atwhich said computer is mounted.
 49. A system according to claim 48,further comprising communication means for performing communicationbetween said computer and said expansion unit, and wherein said sensoroutputs a signal representing the temperature of said processor to saidexpansion unit through said communication means, and said computerincludes means for controlling a clock supplied to said processor so asto decrease an operating speed of said processor when the temperature ofsaid processor, which is sent through said communication means, exceedsa first temperature.
 50. A system according to claim 48, furthercomprising communication means for performing communication between saidcomputer and said expansion unit, and a nonvolatile memory, and whereinsaid sensor outputs a signal representing the temperature of saidprocessor to said computer through said communication means, and saidcomputer includes means for causing said nonvolatile memory to storeinformation necessary for resuming processing which is being executed,thereby powering off said computer when the temperature of saidprocessor, which is sent through said communication means exceeds asecond temperature.